Object
The class to access PostgreSQL RDBMS, based on the libpq interface, provides convenient OO methods to interact with PostgreSQL.
For example, to send query to the database on the localhost:
require 'pg' conn = PGconn.open(:dbname => 'test') res = conn.exec('SELECT $1 AS a, $2 AS b, $3 AS c',[1, 2, nil]) # Equivalent to: # res = conn.exec('SELECT 1 AS a, 2 AS b, NULL AS c')
See the PGresult class for information on working with the results of a query.
Library version
Connection succeeded
Connection failed
Waiting for connection to be made.
Connection OK; waiting to send.
Waiting for a response from the server.
Received authentication; waiting for backend start-up to finish.
Negotiating SSL encryption.
Negotiating environment-driven parameter settings.
Async connection is waiting to read
Async connection is waiting to write
Async connection failed or was reset
Async connection succeeded
Transaction is currently idle (#)
Transaction is currently active; query has been sent to the server, but not yet completed. (#)
Transaction is currently idle, in a valid transaction block (#)
Transaction is currently idle, in a failed transaction block (#)
Transaction’s connection is bad (#)
Terse error verbosity level (#)
Default error verbosity level (#)
Verbose error verbosity level (#)
Flag for # — seek from object start
Flag for # — seek from current position
Flag for # — seek from object end
Returns an array of hashes. Each hash has the keys:
the name of the option
the environment variable to fall back to
the compiled in option as a secondary fallback
the option’s current value, or nil if not known
the label for the field
“” for normal, “D” for debug, and “*” for password
field size
static VALUE pgconn_s_conndefaults(VALUE self) { PQconninfoOption *options = PQconndefaults(); VALUE ary = rb_ary_new(); VALUE hash; int i = 0; for(i = 0; options[i].keyword != NULL; i++) { hash = rb_hash_new(); if(options[i].keyword) rb_hash_aset(hash, ID2SYM(rb_intern("keyword")), rb_str_new2(options[i].keyword)); if(options[i].envvar) rb_hash_aset(hash, ID2SYM(rb_intern("envvar")), rb_str_new2(options[i].envvar)); if(options[i].compiled) rb_hash_aset(hash, ID2SYM(rb_intern("compiled")), rb_str_new2(options[i].compiled)); if(options[i].val) rb_hash_aset(hash, ID2SYM(rb_intern("val")), rb_str_new2(options[i].val)); if(options[i].label) rb_hash_aset(hash, ID2SYM(rb_intern("label")), rb_str_new2(options[i].label)); if(options[i].dispchar) rb_hash_aset(hash, ID2SYM(rb_intern("dispchar")), rb_str_new2(options[i].dispchar)); rb_hash_aset(hash, ID2SYM(rb_intern("dispsize")), INT2NUM(options[i].dispsize)); rb_ary_push(ary, hash); } PQconninfoFree(options); return ary; }
This is an asynchronous version of PGconn.connect().
Use PGconn#connect_poll to poll the status of the connection.
NOTE: this does not set the connection’s client_encoding for you if Encoding.default_internal is set. To set it after the connection is established, call PGconn#internal_encoding=. You can also set it automatically by setting ENV[‘PGCLIENTENCODING’], or include the ‘options’ connection parameter.
static VALUE pgconn_s_connect_start(int argc, VALUE *argv, VALUE self) { PGconn *conn = NULL; VALUE rb_conn; VALUE conninfo; VALUE error; /* * PGconn.connect_start must act as both alloc() and initialize() * because it is not invoked by calling new(). */ rb_conn = pgconn_alloc(rb_cPGconn); conninfo = parse_connect_args(argc, argv, self); conn = PQconnectStart(StringValuePtr(conninfo)); if(conn == NULL) rb_raise(rb_ePGError, "PQconnectStart() unable to allocate structure"); if (PQstatus(conn) == CONNECTION_BAD) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } Check_Type(rb_conn, T_DATA); DATA_PTR(rb_conn) = conn; if (rb_block_given_p()) { return rb_ensure(rb_yield, self, pgconn_finish, self); } return rb_conn; }
This function is intended to be used by client applications that send commands like: +ALTER USER joe PASSWORD ‘pwd’+. The arguments are the cleartext password, and the SQL name of the user it is for.
Return value is the encrypted password.
static VALUE pgconn_s_encrypt_password(VALUE self, VALUE password, VALUE username) { char *encrypted = NULL; VALUE rval = Qnil; Check_Type(password, T_STRING); Check_Type(username, T_STRING); encrypted = PQencryptPassword(StringValuePtr(password), StringValuePtr(username)); rval = rb_str_new2( encrypted ); PQfreemem( encrypted ); OBJ_INFECT( rval, password ); OBJ_INFECT( rval, username ); return rval; }
Connection instance method for versions of 8.1 and higher of libpq uses PQescapeByteaConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeBytea() API function.
Use the instance method version of this function, it is safer than the class method.
Escapes binary data for use within an SQL command with the type bytea.
Certain byte values must be escaped (but all byte values may be escaped) when used as part of a bytea literal in an SQL statement. In general, to escape a byte, it is converted into the three digit octal number equal to the octet value, and preceded by two backslashes. The single quote (’) and backslash () characters have special alternative escape sequences. # performs this operation, escaping only the minimally required bytes.
Consider using exec_params, which avoids the need for passing values inside of SQL commands.
static VALUE pgconn_s_escape_bytea(VALUE self, VALUE str) { unsigned char *from, *to; size_t from_len, to_len; VALUE ret; Check_Type(str, T_STRING); from = (unsigned char*)RSTRING_PTR(str); from_len = RSTRING_LEN(str); if(rb_obj_class(self) == rb_cPGconn) { to = PQescapeByteaConn(get_pgconn(self), from, from_len, &to_len); } else { to = PQescapeBytea( from, from_len, &to_len); } ret = rb_str_new((char*)to, to_len - 1); OBJ_INFECT(ret, str); PQfreemem(to); return ret; }
Connection instance method for versions of 8.1 and higher of libpq uses PQescapeStringConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeString() API function.
Returns a SQL-safe version of the String str. This is the preferred way to make strings safe for inclusion in SQL queries.
Consider using exec_params, which avoids the need for passing values inside of SQL commands.
Encoding of escaped string will be equal to client encoding of connection.
static VALUE pgconn_s_escape(VALUE self, VALUE string) { char *escaped; int size,error; VALUE result; #ifdef M17N_SUPPORTED rb_encoding* enc; #endif Check_Type(string, T_STRING); escaped = ALLOC_N(char, RSTRING_LEN(string) * 2 + 1); if(rb_obj_class(self) == rb_cPGconn) { size = PQescapeStringConn(get_pgconn(self), escaped, RSTRING_PTR(string), RSTRING_LEN(string), &error); if(error) { xfree(escaped); rb_raise(rb_ePGError, "%s", PQerrorMessage(get_pgconn(self))); } } else { size = PQescapeString(escaped, RSTRING_PTR(string), RSTRING_LEN(string)); } result = rb_str_new(escaped, size); xfree(escaped); OBJ_INFECT(result, string); #ifdef M17N_SUPPORTED if(rb_obj_class(self) == rb_cPGconn) { enc = pgconn_get_client_encoding_as_rb_encoding(get_pgconn(self)); } else { enc = rb_enc_get(string); } rb_enc_associate(result, enc); #endif return result; }
Returns true if libpq is thread safe, false otherwise.
static VALUE pgconn_s_isthreadsafe(VALUE self) { return PQisthreadsafe() ? Qtrue : Qfalse; }
Create a connection to the specified server.
server hostname
server address (avoids hostname lookup, overrides host)
server port number
connecting database name
login user name
login password
maximum time to wait for connection to succeed
backend options
(ignored in newer versions of PostgreSQL)
(disable|allow|prefer|require)
kerberos service name
GSS library to use for GSSAPI authentication
service name to use for additional parameters
Examples:
# As a Hash PGconn.connect( :dbname => 'test', :port => 5432 ) # As a String PGconn.connect( "dbname=test port=5432" ) # As an Array PGconn.connect( nil, 5432, nil, nil, 'test', nil, nil )
If the Ruby default internal encoding is set (i.e., Encoding.default_internal != nil), the connection will have its client_encoding set accordingly.
@raises [PGError] if the connection fails.
static VALUE pgconn_init(int argc, VALUE *argv, VALUE self) { PGconn *conn = NULL; VALUE conninfo; VALUE error; #ifdef M17N_SUPPORTED rb_encoding *enc; const char *encname; #endif conninfo = parse_connect_args(argc, argv, self); conn = PQconnectdb(StringValuePtr(conninfo)); if(conn == NULL) rb_raise(rb_ePGError, "PQconnectStart() unable to allocate structure"); Check_Type(self, T_DATA); DATA_PTR(self) = conn; if (PQstatus(conn) == CONNECTION_BAD) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } #ifdef M17N_SUPPORTED /* If Ruby has its Encoding.default_internal set, set PostgreSQL's client_encoding * to match */ if (( enc = rb_default_internal_encoding() )) { encname = pgconn_get_rb_encoding_as_pg_encname( enc ); if ( PQsetClientEncoding(conn, encname) != 0 ) rb_warn( "Failed to set the default_internal encoding to %s: '%s'", encname, PQerrorMessage(conn) ); } #endif if (rb_block_given_p()) { return rb_ensure(rb_yield, self, pgconn_finish, self); } return self; }
Returns a string that is safe for inclusion in a SQL query as an identifier. Note: this is not a quote function for values, but for identifiers.
For example, in a typical SQL query: SELECT FOO FROM MYTABLE The identifier FOO is folded to lower case, so it actually means foo. If you really want to access the case-sensitive field name FOO, use this function like PGconn.quote_ident('FOO'), which will return "FOO" (with double-quotes). PostgreSQL will see the double-quotes, and it will not fold to lower case.
Similarly, this function also protects against special characters, and other things that might allow SQL injection if the identifier comes from an untrusted source.
static VALUE pgconn_s_quote_ident(VALUE self, VALUE in_str) { VALUE ret; char *str = StringValuePtr(in_str); /* result size at most NAMEDATALEN*2 plus surrounding * double-quotes. */ char buffer[NAMEDATALEN*2+2]; unsigned int i=0,j=0; if(strlen(str) >= NAMEDATALEN) { rb_raise(rb_eArgError, "Input string is longer than NAMEDATALEN-1 (%d)", NAMEDATALEN-1); } buffer[j++] = '"'; for(i = 0; i < strlen(str) && str[i]; i++) { if(str[i] == '"') buffer[j++] = '"'; buffer[j++] = str[i]; } buffer[j++] = '"'; ret = rb_str_new(buffer,j); OBJ_INFECT(ret, in_str); return ret; }
Converts an escaped string representation of binary data into binary data — the reverse of #. This is needed when retrieving bytea data in text format, but not when retrieving it in binary format.
static VALUE pgconn_s_unescape_bytea(VALUE self, VALUE str) { unsigned char *from, *to; size_t to_len; VALUE ret; Check_Type(str, T_STRING); from = (unsigned char*)StringValuePtr(str); to = PQunescapeBytea(from, &to_len); ret = rb_str_new((char*)to, to_len); OBJ_INFECT(ret, str); PQfreemem(to); return ret; }
This function has the same behavior as +PGconn#exec+, except that it’s implemented using asynchronous command processing and ruby’s rb_thread_select in order to allow other threads to process while waiting for the server to complete the request.
static VALUE pgconn_async_exec(int argc, VALUE *argv, VALUE self) { VALUE rb_pgresult = Qnil; /* remove any remaining results from the queue */ pgconn_get_last_result( self ); pgconn_send_query( argc, argv, self ); pgconn_block( 0, NULL, self ); rb_pgresult = pgconn_get_last_result( self ); if ( rb_block_given_p() ) { return rb_ensure( rb_yield, rb_pgresult, pgresult_clear, rb_pgresult ); } return rb_pgresult; }
Returns the process ID of the backend server process for this connection. Note that this is a PID on database server host.
static VALUE pgconn_backend_pid(VALUE self) { return INT2NUM(PQbackendPID(get_pgconn(self))); }
Blocks until the server is no longer busy, or until the optional timeout is reached, whichever comes first. timeout is measured in seconds and can be fractional.
Returns false if timeout is reached, true otherwise.
If true is returned, conn.is_busy will return false and conn.get_result will not block.
static VALUE pgconn_block( int argc, VALUE *argv, VALUE self )
Requests cancellation of the command currently being processed.
Returns nil on success, or a string containing the error message if a failure occurs.
static VALUE pgconn_cancel(VALUE self) { char errbuf[256]; PGcancel *cancel; VALUE retval; int ret; cancel = PQgetCancel(get_pgconn(self)); if(cancel == NULL) rb_raise(rb_ePGError,"Invalid connection!"); ret = PQcancel(cancel, errbuf, 256); if(ret == 1) retval = Qnil; else retval = rb_str_new2(errbuf); PQfreeCancel(cancel); return retval; }
Returns an array of hashes. Each hash has the keys:
the name of the option
the environment variable to fall back to
the compiled in option as a secondary fallback
the option’s current value, or nil if not known
the label for the field
“” for normal, “D” for debug, and “*” for password
field size
static VALUE pgconn_s_conndefaults(VALUE self) { PQconninfoOption *options = PQconndefaults(); VALUE ary = rb_ary_new(); VALUE hash; int i = 0; for(i = 0; options[i].keyword != NULL; i++) { hash = rb_hash_new(); if(options[i].keyword) rb_hash_aset(hash, ID2SYM(rb_intern("keyword")), rb_str_new2(options[i].keyword)); if(options[i].envvar) rb_hash_aset(hash, ID2SYM(rb_intern("envvar")), rb_str_new2(options[i].envvar)); if(options[i].compiled) rb_hash_aset(hash, ID2SYM(rb_intern("compiled")), rb_str_new2(options[i].compiled)); if(options[i].val) rb_hash_aset(hash, ID2SYM(rb_intern("val")), rb_str_new2(options[i].val)); if(options[i].label) rb_hash_aset(hash, ID2SYM(rb_intern("label")), rb_str_new2(options[i].label)); if(options[i].dispchar) rb_hash_aset(hash, ID2SYM(rb_intern("dispchar")), rb_str_new2(options[i].dispchar)); rb_hash_aset(hash, ID2SYM(rb_intern("dispsize")), INT2NUM(options[i].dispsize)); rb_ary_push(ary, hash); } PQconninfoFree(options); return ary; }
Returns one of:
wait until the socket is ready to read
wait until the socket is ready to write
the asynchronous connection has failed
the asynchronous connection is ready
Example:
conn = PGconn.connect_start("dbname=mydatabase") socket = IO.for_fd(conn.socket) status = conn.connect_poll while(status != PGconn::PGRES_POLLING_OK) do # do some work while waiting for the connection to complete if(status == PGconn::PGRES_POLLING_READING) if(not select([socket], [], [], 10.0)) raise "Asynchronous connection timed out!" end elsif(status == PGconn::PGRES_POLLING_WRITING) if(not select([], [socket], [], 10.0)) raise "Asynchronous connection timed out!" end end status = conn.connect_poll end # now conn.status == CONNECTION_OK, and connection # is ready.
static VALUE pgconn_connect_poll(VALUE self) { PostgresPollingStatusType status; status = PQconnectPoll(get_pgconn(self)); return INT2FIX((int)status); }
Returns true if the authentication method required a password, but none was available. false otherwise.
static VALUE pgconn_connection_needs_password(VALUE self) { return PQconnectionNeedsPassword(get_pgconn(self)) ? Qtrue : Qfalse; }
Returns true if the authentication method used a caller-supplied password, false otherwise.
static VALUE pgconn_connection_used_password(VALUE self) { return PQconnectionUsedPassword(get_pgconn(self)) ? Qtrue : Qfalse; }
If input is available from the server, consume it. After calling consume_input, you can check is_busy or notifies to see if the state has changed.
static VALUE pgconn_consume_input(self) VALUE self; { VALUE error; PGconn *conn = get_pgconn(self); /* returns 0 on error */ if(PQconsumeInput(conn) == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
Returns the connected database name.
static VALUE pgconn_db(VALUE self) { char *db = PQdb(get_pgconn(self)); if (!db) return Qnil; return rb_tainted_str_new2(db); }
Retrieve information about the portal portal_name.
static VALUE pgconn_describe_portal(self, stmt_name) VALUE self, stmt_name; { PGresult *result; VALUE rb_pgresult; PGconn *conn = get_pgconn(self); char *stmt; if(stmt_name == Qnil) { stmt = NULL; } else { Check_Type(stmt_name, T_STRING); stmt = StringValuePtr(stmt_name); } result = PQdescribePortal(conn, stmt); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); return rb_pgresult; }
Retrieve information about the prepared statement statement_name.
static VALUE pgconn_describe_prepared(VALUE self, VALUE stmt_name) { PGresult *result; VALUE rb_pgresult; PGconn *conn = get_pgconn(self); char *stmt; if(stmt_name == Qnil) { stmt = NULL; } else { Check_Type(stmt_name, T_STRING); stmt = StringValuePtr(stmt_name); } result = PQdescribePrepared(conn, stmt); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); return rb_pgresult; }
Returns the error message about connection.
static VALUE pgconn_error_message(VALUE self) { char *error = PQerrorMessage(get_pgconn(self)); if (!error) return Qnil; return rb_tainted_str_new2(error); }
Connection instance method for versions of 8.1 and higher of libpq uses PQescapeByteaConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeBytea() API function.
Use the instance method version of this function, it is safer than the class method.
Escapes binary data for use within an SQL command with the type bytea.
Certain byte values must be escaped (but all byte values may be escaped) when used as part of a bytea literal in an SQL statement. In general, to escape a byte, it is converted into the three digit octal number equal to the octet value, and preceded by two backslashes. The single quote (’) and backslash () characters have special alternative escape sequences. # performs this operation, escaping only the minimally required bytes.
Consider using exec_params, which avoids the need for passing values inside of SQL commands.
static VALUE pgconn_s_escape_bytea(VALUE self, VALUE str) { unsigned char *from, *to; size_t from_len, to_len; VALUE ret; Check_Type(str, T_STRING); from = (unsigned char*)RSTRING_PTR(str); from_len = RSTRING_LEN(str); if(rb_obj_class(self) == rb_cPGconn) { to = PQescapeByteaConn(get_pgconn(self), from, from_len, &to_len); } else { to = PQescapeBytea( from, from_len, &to_len); } ret = rb_str_new((char*)to, to_len - 1); OBJ_INFECT(ret, str); PQfreemem(to); return ret; }
Connection instance method for versions of 8.1 and higher of libpq uses PQescapeStringConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeString() API function.
Returns a SQL-safe version of the String str. This is the preferred way to make strings safe for inclusion in SQL queries.
Consider using exec_params, which avoids the need for passing values inside of SQL commands.
Encoding of escaped string will be equal to client encoding of connection.
static VALUE pgconn_s_escape(VALUE self, VALUE string) { char *escaped; int size,error; VALUE result; #ifdef M17N_SUPPORTED rb_encoding* enc; #endif Check_Type(string, T_STRING); escaped = ALLOC_N(char, RSTRING_LEN(string) * 2 + 1); if(rb_obj_class(self) == rb_cPGconn) { size = PQescapeStringConn(get_pgconn(self), escaped, RSTRING_PTR(string), RSTRING_LEN(string), &error); if(error) { xfree(escaped); rb_raise(rb_ePGError, "%s", PQerrorMessage(get_pgconn(self))); } } else { size = PQescapeString(escaped, RSTRING_PTR(string), RSTRING_LEN(string)); } result = rb_str_new(escaped, size); xfree(escaped); OBJ_INFECT(result, string); #ifdef M17N_SUPPORTED if(rb_obj_class(self) == rb_cPGconn) { enc = pgconn_get_client_encoding_as_rb_encoding(get_pgconn(self)); } else { enc = rb_enc_get(string); } rb_enc_associate(result, enc); #endif return result; }
Sends SQL query request specified by sql to PostgreSQL. Returns a PGresult instance on success. On failure, it raises a PGError exception.
params is an optional array of the bind parameters for the SQL query. Each element of the params array may be either:
a hash of the form: {:value => String (value of bind parameter) :type => Fixnum (oid of type of bind parameter) :format => Fixnum (0 for text, 1 for binary) } or, it may be a String. If it is a string, that is equivalent to the hash: { :value => <string value>, :type => 0, :format => 0 }
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.
If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.
For example: “SELECT $1::int“
The optional result_format should be 0 for text results, 1 for binary.
If the optional code block is given, it will be passed result as an argument, and the PGresult object will automatically be cleared when the block terminates. In this instance, conn.exec returns the value of the block.
static VALUE pgconn_exec(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); PGresult *result = NULL; VALUE rb_pgresult; VALUE command, params, in_res_fmt; VALUE param, param_type, param_value, param_format; VALUE param_value_tmp; VALUE sym_type, sym_value, sym_format; VALUE gc_array; int i=0; int nParams; Oid *paramTypes; char ** paramValues; int *paramLengths; int *paramFormats; int resultFormat; rb_scan_args(argc, argv, "12", &command, ¶ms, &in_res_fmt); Check_Type(command, T_STRING); /* If called with no parameters, use PQexec */ if(NIL_P(params)) { result = PQexec(conn, StringValuePtr(command)); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); if (rb_block_given_p()) { return rb_ensure(rb_yield, rb_pgresult, pgresult_clear, rb_pgresult); } return rb_pgresult; } /* If called with parameters, and optionally result_format, * use PQexecParams */ Check_Type(params, T_ARRAY); if(NIL_P(in_res_fmt)) { resultFormat = 0; } else { resultFormat = NUM2INT(in_res_fmt); } gc_array = rb_ary_new(); rb_gc_register_address(&gc_array); sym_type = ID2SYM(rb_intern("type")); sym_value = ID2SYM(rb_intern("value")); sym_format = ID2SYM(rb_intern("format")); nParams = RARRAY_LEN(params); paramTypes = ALLOC_N(Oid, nParams); paramValues = ALLOC_N(char *, nParams); paramLengths = ALLOC_N(int, nParams); paramFormats = ALLOC_N(int, nParams); for(i = 0; i < nParams; i++) { param = rb_ary_entry(params, i); if (TYPE(param) == T_HASH) { param_type = rb_hash_aref(param, sym_type); param_value_tmp = rb_hash_aref(param, sym_value); if(param_value_tmp == Qnil) param_value = param_value_tmp; else param_value = rb_obj_as_string(param_value_tmp); param_format = rb_hash_aref(param, sym_format); } else { param_type = Qnil; if(param == Qnil) param_value = param; else param_value = rb_obj_as_string(param); param_format = Qnil; } if(param_type == Qnil) paramTypes[i] = 0; else paramTypes[i] = NUM2INT(param_type); if(param_value == Qnil) { paramValues[i] = NULL; paramLengths[i] = 0; } else { Check_Type(param_value, T_STRING); /* make sure param_value doesn't get freed by the GC */ rb_ary_push(gc_array, param_value); paramValues[i] = StringValuePtr(param_value); paramLengths[i] = RSTRING_LEN(param_value); } if(param_format == Qnil) paramFormats[i] = 0; else paramFormats[i] = NUM2INT(param_format); } result = PQexecParams(conn, StringValuePtr(command), nParams, paramTypes, (const char * const *)paramValues, paramLengths, paramFormats, resultFormat); rb_gc_unregister_address(&gc_array); xfree(paramTypes); xfree(paramValues); xfree(paramLengths); xfree(paramFormats); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); if (rb_block_given_p()) { return rb_ensure(rb_yield, rb_pgresult, pgresult_clear, rb_pgresult); } return rb_pgresult; }
Execute prepared named statement specified by statement_name. Returns a PGresult instance on success. On failure, it raises a PGError exception.
params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:
a hash of the form: {:value => String (value of bind parameter) :format => Fixnum (0 for text, 1 for binary) } or, it may be a String. If it is a string, that is equivalent to the hash: { :value => <string value>, :format => 0 }
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.
The optional result_format should be 0 for text results, 1 for binary.
If the optional code block is given, it will be passed result as an argument, and the PGresult object will automatically be cleared when the block terminates. In this instance, conn.exec_prepared returns the value of the block.
static VALUE pgconn_exec_prepared(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); PGresult *result = NULL; VALUE rb_pgresult; VALUE name, params, in_res_fmt; VALUE param, param_value, param_format; VALUE param_value_tmp; VALUE sym_value, sym_format; VALUE gc_array; int i = 0; int nParams; char ** paramValues; int *paramLengths; int *paramFormats; int resultFormat; rb_scan_args(argc, argv, "12", &name, ¶ms, &in_res_fmt); Check_Type(name, T_STRING); if(NIL_P(params)) { params = rb_ary_new2(0); resultFormat = 0; } else { Check_Type(params, T_ARRAY); } if(NIL_P(in_res_fmt)) { resultFormat = 0; } else { resultFormat = NUM2INT(in_res_fmt); } gc_array = rb_ary_new(); rb_gc_register_address(&gc_array); sym_value = ID2SYM(rb_intern("value")); sym_format = ID2SYM(rb_intern("format")); nParams = RARRAY_LEN(params); paramValues = ALLOC_N(char *, nParams); paramLengths = ALLOC_N(int, nParams); paramFormats = ALLOC_N(int, nParams); for(i = 0; i < nParams; i++) { param = rb_ary_entry(params, i); if (TYPE(param) == T_HASH) { param_value_tmp = rb_hash_aref(param, sym_value); if(param_value_tmp == Qnil) param_value = param_value_tmp; else param_value = rb_obj_as_string(param_value_tmp); param_format = rb_hash_aref(param, sym_format); } else { if(param == Qnil) param_value = param; else param_value = rb_obj_as_string(param); param_format = INT2NUM(0); } if(param_value == Qnil) { paramValues[i] = NULL; paramLengths[i] = 0; } else { Check_Type(param_value, T_STRING); /* make sure param_value doesn't get freed by the GC */ rb_ary_push(gc_array, param_value); paramValues[i] = StringValuePtr(param_value); paramLengths[i] = RSTRING_LEN(param_value); } if(param_format == Qnil) paramFormats[i] = 0; else paramFormats[i] = NUM2INT(param_format); } result = PQexecPrepared(conn, StringValuePtr(name), nParams, (const char * const *)paramValues, paramLengths, paramFormats, resultFormat); rb_gc_unregister_address(&gc_array); xfree(paramValues); xfree(paramLengths); xfree(paramFormats); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); if (rb_block_given_p()) { return rb_ensure(rb_yield, rb_pgresult, pgresult_clear, rb_pgresult); } return rb_pgresult; }
defined in Ruby 1.9 or later.
Returns the server_encoding of the connected database as a Ruby Encoding object.
Maps ‘SQL_ASCII’ to ASCII-8BIT.
static VALUE pgconn_external_encoding(VALUE self) { VALUE enc; enc = rb_iv_get(self, "@external_encoding"); if (RTEST(enc)) { return enc; } else { int i; VALUE query = rb_usascii_str_new_cstr("SHOW server_encoding"); VALUE pgresult = pgconn_exec(1, &query, self); VALUE enc_name = rb_ensure(enc_server_encoding_getvalue, pgresult, pgresult_clear, pgresult); if (strcmp("SQL_ASCII", StringValuePtr(enc_name)) == 0) { enc = rb_enc_from_encoding(rb_ascii8bit_encoding()); goto cache; } for (i = 0; i < sizeof(enc_pg2ruby_mapping)/sizeof(enc_pg2ruby_mapping[0]); ++i) { if (strcmp(StringValuePtr(enc_name), enc_pg2ruby_mapping[i][0]) == 0) { enc = rb_enc_from_encoding(rb_enc_find(enc_pg2ruby_mapping[i][1])); goto cache; } } /* Ruby 1.9.1 does not supoort JOHAB */ if (strcmp(StringValuePtr(enc_name), "JOHAB") == 0) { enc = rb_enc_from_encoding(find_or_create_johab()); goto cache; } /* fallback */ enc = rb_enc_from_encoding(rb_enc_find(StringValuePtr(enc_name))); } cache: rb_iv_set(self, "@external_encoding", enc); return enc; }
Closes the backend connection.
static VALUE pgconn_finish(VALUE self) { PQfinish(get_pgconn(self)); DATA_PTR(self) = NULL; return Qnil; }
Attempts to flush any queued output data to the server. Returns true if data is successfully flushed, false if not (can only return false if connection is nonblocking. Raises PGError exception if some other failure occurred.
static VALUE pgconn_flush(self) VALUE self; { PGconn *conn = get_pgconn(self); int ret; VALUE error; ret = PQflush(conn); if(ret == -1) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return (ret) ? Qfalse : Qtrue; }
Returns the client encoding as a String.
static VALUE pgconn_get_client_encoding(VALUE self) { char *encoding = (char *)pg_encoding_to_char(PQclientEncoding(get_pgconn(self))); return rb_tainted_str_new2(encoding); }
Return a string containing one row of data, nil if the copy is done, or false if the call would block (only possible if async is true).
static VALUE pgconn_get_copy_data(int argc, VALUE *argv, VALUE self ) { VALUE async_in; VALUE error; VALUE result_str; int ret; int async; char *buffer; PGconn *conn = get_pgconn(self); if (rb_scan_args(argc, argv, "01", &async_in) == 0) async = 0; else async = (async_in == Qfalse || async_in == Qnil) ? 0 : 1; ret = PQgetCopyData(conn, &buffer, async); if(ret == -2) { // error error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } if(ret == -1) { // No data left return Qnil; } if(ret == 0) { // would block return Qfalse; } result_str = rb_tainted_str_new(buffer, ret); PQfreemem(buffer); return result_str; }
This function retrieves all available results on the current connection (from previously issued asynchronous commands like +send_query()+) and returns the last non-NULL result, or nil if no results are available.
This function is similar to +PGconn#get_result+ except that it is designed to get one and only one result.
static VALUE pgconn_get_last_result(VALUE self) { PGconn *conn = get_pgconn(self); VALUE rb_pgresult = Qnil; PGresult *cur, *prev; cur = prev = NULL; while ((cur = PQgetResult(conn)) != NULL) { int status; if (prev) PQclear(prev); prev = cur; status = PQresultStatus(cur); if (status == PGRES_COPY_OUT || status == PGRES_COPY_IN) break; } if (prev) { rb_pgresult = new_pgresult(prev, conn); pgresult_check(self, rb_pgresult); } return rb_pgresult; }
Blocks waiting for the next result from a call to +PGconn#send_query+ (or another asynchronous command), and returns it. Returns nil if no more results are available.
Note: call this function repeatedly until it returns nil, or else you will not be able to issue further commands.
If the optional code block is given, it will be passed result as an argument, and the PGresult object will automatically be cleared when the block terminates. In this instance, conn.exec returns the value of the block.
static VALUE pgconn_get_result(VALUE self) { PGconn *conn = get_pgconn(self); PGresult *result; VALUE rb_pgresult; result = PQgetResult(conn); if(result == NULL) return Qnil; rb_pgresult = new_pgresult(result, conn); if (rb_block_given_p()) { return rb_ensure(rb_yield, rb_pgresult, pgresult_clear, rb_pgresult); } return rb_pgresult; }
Returns the connected server name.
static VALUE pgconn_host(VALUE self) { char *host = PQhost(get_pgconn(self)); if (!host) return Qnil; return rb_tainted_str_new2(host); }
defined in Ruby 1.9 or later.
Returns:
an Encoding - client_encoding of the connection as a Ruby Encoding object.
nil - the client_encoding is ‘SQL_ASCII‘
static VALUE pgconn_internal_encoding(VALUE self) { return rb_enc_from_encoding(pgconn_get_client_encoding_as_rb_encoding(get_pgconn(self))); }
A wrapper of +PGconn#set_client_encoding+. defined in Ruby 1.9 or later.
value can be one of:
an Encoding
a String - a name of Encoding
nil - sets ‘SQL_ASCII’ to the client_encoding.
static VALUE pgconn_internal_encoding_set(VALUE self, VALUE enc) { if (NIL_P(enc)) { pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("SQL_ASCII")); return enc; } else if (TYPE(enc) == T_STRING && strcasecmp("JOHAB", RSTRING_PTR(enc)) == 0) { pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("JOHAB")); return enc; } else { int i; const char *name; name = rb_enc_name(rb_to_encoding(enc)); /* sequential search becuase rarely called */ for (i = 0; i < sizeof(enc_pg2ruby_mapping)/sizeof(enc_pg2ruby_mapping[0]); ++i) { if (strcmp(name, enc_pg2ruby_mapping[i][1]) == 0) { if (PQsetClientEncoding(get_pgconn(self), enc_pg2ruby_mapping[i][0]) == -1) { VALUE server_encoding = pgconn_external_encoding(self); rb_raise(rb_eEncCompatError, "imcompatible character encodings: %s and %s", rb_enc_name(rb_to_encoding(server_encoding)), enc_pg2ruby_mapping[i][0]); } return enc; } } /* Ruby 1.9.1 does not support JOHAB */ if (strcasecmp(name, "JOHAB") == 0) { pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("JOHAB")); return enc; } } enc = rb_inspect(enc); rb_raise(rb_ePGError, "unknown encoding: %s", StringValuePtr(enc)); }
Returns true if a command is busy, that is, if PQgetResult would block. Otherwise returns false.
static VALUE pgconn_is_busy(self) VALUE self; { return PQisBusy(get_pgconn(self)) ? Qtrue : Qfalse; }
Returns true if a command is busy, that is, if PQgetResult would block. Otherwise returns false.
static VALUE pgconn_isnonblocking(self) VALUE self; { return PQisnonblocking(get_pgconn(self)) ? Qtrue : Qfalse; }
Closes the postgres large object of lo_desc.
static VALUE pgconn_loclose(VALUE self, VALUE in_lo_desc) { PGconn *conn = get_pgconn(self); int lo_desc = NUM2INT(in_lo_desc); if(lo_close(conn,lo_desc) < 0) rb_raise(rb_ePGError,"lo_close failed"); return Qnil; }
Creates a large object with mode mode. Returns a large object Oid. On failure, it raises PGError exception.
static VALUE pgconn_locreat(int argc, VALUE *argv, VALUE self) { Oid lo_oid; int mode; VALUE nmode; PGconn *conn = get_pgconn(self); if (rb_scan_args(argc, argv, "01", &nmode) == 0) mode = INV_READ; else mode = NUM2INT(nmode); lo_oid = lo_creat(conn, mode); if (lo_oid == 0) rb_raise(rb_ePGError, "lo_creat failed"); return INT2FIX(lo_oid); }
Creates a large object with oid oid. Returns the large object Oid. On failure, it raises PGError exception.
static VALUE pgconn_locreate(VALUE self, VALUE in_lo_oid) { Oid ret, lo_oid; PGconn *conn = get_pgconn(self); lo_oid = NUM2INT(in_lo_oid); ret = lo_create(conn, in_lo_oid); if (ret == InvalidOid) rb_raise(rb_ePGError, "lo_create failed"); return INT2FIX(ret); }
Saves a large object of oid to a file.
static VALUE pgconn_loexport(VALUE self, VALUE lo_oid, VALUE filename) { PGconn *conn = get_pgconn(self); int oid; Check_Type(filename, T_STRING); oid = NUM2INT(lo_oid); if (oid < 0) { rb_raise(rb_ePGError, "invalid large object oid %d",oid); } if (lo_export(conn, oid, StringValuePtr(filename)) < 0) { rb_raise(rb_ePGError, "%s", PQerrorMessage(conn)); } return Qnil; }
Import a file to a large object. Returns a large object Oid.
On failure, it raises a PGError exception.
static VALUE pgconn_loimport(VALUE self, VALUE filename) { Oid lo_oid; PGconn *conn = get_pgconn(self); Check_Type(filename, T_STRING); lo_oid = lo_import(conn, StringValuePtr(filename)); if (lo_oid == 0) { rb_raise(rb_ePGError, "%s", PQerrorMessage(conn)); } return INT2FIX(lo_oid); }
Move the large object pointer lo_desc to offset offset. Valid values for whence are SEEK_SET, SEEK_CUR, and SEEK_END. (Or 0, 1, or 2.)
static VALUE pgconn_lolseek(VALUE self, VALUE in_lo_desc, VALUE offset, VALUE whence) { PGconn *conn = get_pgconn(self); int lo_desc = NUM2INT(in_lo_desc); int ret; if((ret = lo_lseek(conn, lo_desc, NUM2INT(offset), NUM2INT(whence))) < 0) { rb_raise(rb_ePGError, "lo_lseek failed"); } return INT2FIX(ret); }
Open a large object of oid. Returns a large object descriptor instance on success. The mode argument specifies the mode for the opened large object,which is either INV_READ, or INV_WRITE.
If mode is omitted, the default is INV_READ.
static VALUE pgconn_loopen(int argc, VALUE *argv, VALUE self) { Oid lo_oid; int fd, mode; VALUE nmode, selfid; PGconn *conn = get_pgconn(self); rb_scan_args(argc, argv, "11", &selfid, &nmode); lo_oid = NUM2INT(selfid); if(NIL_P(nmode)) mode = INV_READ; else mode = NUM2INT(nmode); if((fd = lo_open(conn, lo_oid, mode)) < 0) { rb_raise(rb_ePGError, "can't open large object: %s", PQerrorMessage(conn)); } return INT2FIX(fd); }
Attempts to read len bytes from large object lo_desc, returns resulting data.
static VALUE pgconn_loread(VALUE self, VALUE in_lo_desc, VALUE in_len) { int ret; PGconn *conn = get_pgconn(self); int len = NUM2INT(in_len); int lo_desc = NUM2INT(in_lo_desc); VALUE str; char *buffer; buffer = ALLOC_N(char, len); if(buffer == NULL) rb_raise(rb_eNoMemError, "ALLOC failed!"); if (len < 0){ rb_raise(rb_ePGError,"nagative length %d given", len); } if((ret = lo_read(conn, lo_desc, buffer, len)) < 0) rb_raise(rb_ePGError, "lo_read failed"); if(ret == 0) { xfree(buffer); return Qnil; } str = rb_tainted_str_new(buffer, ret); xfree(buffer); return str; }
Returns the current position of the large object lo_desc.
static VALUE pgconn_lotell(VALUE self, VALUE in_lo_desc) { int position; PGconn *conn = get_pgconn(self); int lo_desc = NUM2INT(in_lo_desc); if((position = lo_tell(conn, lo_desc)) < 0) rb_raise(rb_ePGError,"lo_tell failed"); return INT2FIX(position); }
Truncates the large object lo_desc to size len.
static VALUE pgconn_lotruncate(VALUE self, VALUE in_lo_desc, VALUE in_len) { PGconn *conn = get_pgconn(self); int lo_desc = NUM2INT(in_lo_desc); size_t len = NUM2INT(in_len); if(lo_truncate(conn,lo_desc,len) < 0) rb_raise(rb_ePGError,"lo_truncate failed"); return Qnil; }
Unlinks (deletes) the postgres large object of oid.
static VALUE pgconn_lounlink(VALUE self, VALUE in_oid) { PGconn *conn = get_pgconn(self); int oid = NUM2INT(in_oid); if (oid < 0) rb_raise(rb_ePGError, "invalid oid %d",oid); if(lo_unlink(conn,oid) < 0) rb_raise(rb_ePGError,"lo_unlink failed"); return Qnil; }
Writes the string buffer to the large object lo_desc. Returns the number of bytes written.
static VALUE pgconn_lowrite(VALUE self, VALUE in_lo_desc, VALUE buffer) { int n; PGconn *conn = get_pgconn(self); int fd = NUM2INT(in_lo_desc); Check_Type(buffer, T_STRING); if( RSTRING_LEN(buffer) < 0) { rb_raise(rb_ePGError, "write buffer zero string"); } if((n = lo_write(conn, fd, StringValuePtr(buffer), RSTRING_LEN(buffer))) < 0) { rb_raise(rb_ePGError, "lo_write failed: %s", PQerrorMessage(conn)); } return INT2FIX(n); }
Constructs and empty PGresult with status status. status may be one of:
PGRES_EMPTY_QUERY
PGRES_COMMAND_OK
PGRES_TUPLES_OK
PGRES_COPY_OUT
PGRES_COPY_IN
PGRES_BAD_RESPONSE
PGRES_NONFATAL_ERROR
PGRES_FATAL_ERROR
static VALUE pgconn_make_empty_pgresult(VALUE self, VALUE status) { PGresult *result; VALUE rb_pgresult; PGconn *conn = get_pgconn(self); result = PQmakeEmptyPGresult(conn, NUM2INT(status)); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); return rb_pgresult; }
Returns a hash of the unprocessed notifiers. If there is no unprocessed notifier, it returns nil.
static VALUE pgconn_notifies(VALUE self) { PGconn* conn = get_pgconn(self); PGnotify *notify; VALUE hash; VALUE sym_relname, sym_be_pid, sym_extra; VALUE relname, be_pid, extra; sym_relname = ID2SYM(rb_intern("relname")); sym_be_pid = ID2SYM(rb_intern("be_pid")); sym_extra = ID2SYM(rb_intern("extra")); notify = PQnotifies(conn); if (notify == NULL) { return Qnil; } hash = rb_hash_new(); relname = rb_tainted_str_new2(notify->relname); be_pid = INT2NUM(notify->be_pid); extra = rb_tainted_str_new2(PGNOTIFY_EXTRA(notify)); rb_hash_aset(hash, sym_relname, relname); rb_hash_aset(hash, sym_be_pid, be_pid); rb_hash_aset(hash, sym_extra, extra); PQfreemem(notify); return hash; }
Returns backend option string.
static VALUE pgconn_options(VALUE self) { char *options = PQoptions(get_pgconn(self)); if (!options) return Qnil; return rb_tainted_str_new2(options); }
Returns the setting of parameter param_name, where param_name is one of
server_encoding
client_encoding
is_superuser
session_authorization
DateStyle
TimeZone
integer_datetimes
standard_conforming_strings
Returns nil if the value of the parameter is not known.
static VALUE pgconn_parameter_status(VALUE self, VALUE param_name) { const char *ret = PQparameterStatus(get_pgconn(self), StringValuePtr(param_name)); if(ret == NULL) return Qnil; else return rb_tainted_str_new2(ret); }
Returns the authenticated user name.
static VALUE pgconn_pass(VALUE self) { char *user = PQpass(get_pgconn(self)); if (!user) return Qnil; return rb_tainted_str_new2(user); }
Returns the connected server port number.
static VALUE pgconn_port(VALUE self) { char* port = PQport(get_pgconn(self)); return INT2NUM(atol(port)); }
Prepares statement sql with name name to be executed later. Returns a PGresult instance on success. On failure, it raises a PGError exception.
param_types is an optional parameter to specify the Oids of the types of the parameters.
If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.
For example: “SELECT $1::int“
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.
static VALUE pgconn_prepare(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); PGresult *result = NULL; VALUE rb_pgresult; VALUE name, command, in_paramtypes; VALUE param; int i = 0; int nParams = 0; Oid *paramTypes = NULL; rb_scan_args(argc, argv, "21", &name, &command, &in_paramtypes); Check_Type(name, T_STRING); Check_Type(command, T_STRING); if(! NIL_P(in_paramtypes)) { Check_Type(in_paramtypes, T_ARRAY); nParams = RARRAY_LEN(in_paramtypes); paramTypes = ALLOC_N(Oid, nParams); for(i = 0; i < nParams; i++) { param = rb_ary_entry(in_paramtypes, i); Check_Type(param, T_FIXNUM); if(param == Qnil) paramTypes[i] = 0; else paramTypes[i] = NUM2INT(param); } } result = PQprepare(conn, StringValuePtr(name), StringValuePtr(command), nParams, paramTypes); xfree(paramTypes); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); return rb_pgresult; }
The 3.0 protocol will normally be used when communicating with PostgreSQL 7.4 or later servers; pre-7.4 servers support only protocol 2.0. (Protocol 1.0 is obsolete and not supported by libpq.)
static VALUE pgconn_protocol_version(VALUE self) { return INT2NUM(PQprotocolVersion(get_pgconn(self))); }
Transmits buffer as copy data to the server. Returns true if the data was sent, false if it was not sent (false is only possible if the connection is in nonblocking mode, and this command would block).
Raises an exception if an error occurs.
static VALUE pgconn_put_copy_data(self, buffer) VALUE self, buffer; { int ret; VALUE error; PGconn *conn = get_pgconn(self); Check_Type(buffer, T_STRING); ret = PQputCopyData(conn, RSTRING_PTR(buffer), RSTRING_LEN(buffer)); if(ret == -1) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return (ret) ? Qtrue : Qfalse; }
Sends end-of-data indication to the server.
error_message is an optional parameter, and if set, forces the COPY command to fail with the string error_message.
Returns true if the end-of-data was sent, false if it was not sent (false is only possible if the connection is in nonblocking mode, and this command would block).
static VALUE pgconn_put_copy_end(int argc, VALUE *argv, VALUE self) { VALUE str; VALUE error; int ret; char *error_message = NULL; PGconn *conn = get_pgconn(self); if (rb_scan_args(argc, argv, "01", &str) == 0) error_message = NULL; else error_message = StringValuePtr(str); ret = PQputCopyEnd(conn, error_message); if(ret == -1) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return (ret) ? Qtrue : Qfalse; }
Returns a string that is safe for inclusion in a SQL query as an identifier. Note: this is not a quote function for values, but for identifiers.
For example, in a typical SQL query: SELECT FOO FROM MYTABLE The identifier FOO is folded to lower case, so it actually means foo. If you really want to access the case-sensitive field name FOO, use this function like PGconn.quote_ident('FOO'), which will return "FOO" (with double-quotes). PostgreSQL will see the double-quotes, and it will not fold to lower case.
Similarly, this function also protects against special characters, and other things that might allow SQL injection if the identifier comes from an untrusted source.
static VALUE pgconn_s_quote_ident(VALUE self, VALUE in_str) { VALUE ret; char *str = StringValuePtr(in_str); /* result size at most NAMEDATALEN*2 plus surrounding * double-quotes. */ char buffer[NAMEDATALEN*2+2]; unsigned int i=0,j=0; if(strlen(str) >= NAMEDATALEN) { rb_raise(rb_eArgError, "Input string is longer than NAMEDATALEN-1 (%d)", NAMEDATALEN-1); } buffer[j++] = '"'; for(i = 0; i < strlen(str) && str[i]; i++) { if(str[i] == '"') buffer[j++] = '"'; buffer[j++] = str[i]; } buffer[j++] = '"'; ret = rb_str_new(buffer,j); OBJ_INFECT(ret, in_str); return ret; }
Resets the backend connection. This method closes the backend connection and tries to re-connect.
static VALUE pgconn_reset(VALUE self) { PQreset(get_pgconn(self)); return self; }
Checks the status of a connection reset operation. See PGconn#connect_start and PGconn#connect_poll for usage information and return values.
static VALUE pgconn_reset_poll(VALUE self) { PostgresPollingStatusType status; status = PQresetPoll(get_pgconn(self)); return INT2FIX((int)status); }
Initiate a connection reset in a nonblocking manner. This will close the current connection and attempt to reconnect using the same connection parameters. Use PGconn#reset_poll to check the status of the connection reset.
static VALUE pgconn_reset_start(VALUE self) { if(PQresetStart(get_pgconn(self)) == 0) rb_raise(rb_ePGError, "reset has failed"); return Qnil; }
Asynchronously send command to the server. Does not block. Use in combination with conn.get_result.
static VALUE pgconn_send_describe_portal(VALUE self, VALUE portal) { VALUE error; PGconn *conn = get_pgconn(self); /* returns 0 on failure */ if(PQsendDescribePortal(conn,StringValuePtr(portal)) == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
Asynchronously send command to the server. Does not block. Use in combination with conn.get_result.
static VALUE pgconn_send_describe_prepared(VALUE self, VALUE stmt_name) { VALUE error; PGconn *conn = get_pgconn(self); /* returns 0 on failure */ if(PQsendDescribePrepared(conn,StringValuePtr(stmt_name)) == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
Prepares statement sql with name name to be executed later. Sends prepare command asynchronously, and returns immediately. On failure, it raises a PGError exception.
param_types is an optional parameter to specify the Oids of the types of the parameters.
If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.
For example: “SELECT $1::int“
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.
static VALUE pgconn_send_prepare(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); int result; VALUE name, command, in_paramtypes; VALUE param; VALUE error; int i = 0; int nParams = 0; Oid *paramTypes = NULL; rb_scan_args(argc, argv, "21", &name, &command, &in_paramtypes); Check_Type(name, T_STRING); Check_Type(command, T_STRING); if(! NIL_P(in_paramtypes)) { Check_Type(in_paramtypes, T_ARRAY); nParams = RARRAY_LEN(in_paramtypes); paramTypes = ALLOC_N(Oid, nParams); for(i = 0; i < nParams; i++) { param = rb_ary_entry(in_paramtypes, i); Check_Type(param, T_FIXNUM); if(param == Qnil) paramTypes[i] = 0; else paramTypes[i] = NUM2INT(param); } } result = PQsendPrepare(conn, StringValuePtr(name), StringValuePtr(command), nParams, paramTypes); xfree(paramTypes); if(result == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
Sends SQL query request specified by sql to PostgreSQL for asynchronous processing, and immediately returns. On failure, it raises a PGError exception.
params is an optional array of the bind parameters for the SQL query. Each element of the params array may be either:
a hash of the form: {:value => String (value of bind parameter) :type => Fixnum (oid of type of bind parameter) :format => Fixnum (0 for text, 1 for binary) } or, it may be a String. If it is a string, that is equivalent to the hash: { :value => <string value>, :type => 0, :format => 0 }
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.
If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.
For example: “SELECT $1::int“
The optional result_format should be 0 for text results, 1 for binary.
static VALUE pgconn_send_query(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); int result; VALUE command, params, in_res_fmt; VALUE param, param_type, param_value, param_format; VALUE param_value_tmp; VALUE sym_type, sym_value, sym_format; VALUE gc_array; VALUE error; int i=0; int nParams; Oid *paramTypes; char ** paramValues; int *paramLengths; int *paramFormats; int resultFormat; rb_scan_args(argc, argv, "12", &command, ¶ms, &in_res_fmt); Check_Type(command, T_STRING); /* If called with no parameters, use PQsendQuery */ if(NIL_P(params)) { if(PQsendQuery(conn,StringValuePtr(command)) == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; } /* If called with parameters, and optionally result_format, * use PQsendQueryParams */ Check_Type(params, T_ARRAY); if(NIL_P(in_res_fmt)) { resultFormat = 0; } else { resultFormat = NUM2INT(in_res_fmt); } gc_array = rb_ary_new(); rb_gc_register_address(&gc_array); sym_type = ID2SYM(rb_intern("type")); sym_value = ID2SYM(rb_intern("value")); sym_format = ID2SYM(rb_intern("format")); nParams = RARRAY_LEN(params); paramTypes = ALLOC_N(Oid, nParams); paramValues = ALLOC_N(char *, nParams); paramLengths = ALLOC_N(int, nParams); paramFormats = ALLOC_N(int, nParams); for(i = 0; i < nParams; i++) { param = rb_ary_entry(params, i); if (TYPE(param) == T_HASH) { param_type = rb_hash_aref(param, sym_type); param_value_tmp = rb_hash_aref(param, sym_value); if(param_value_tmp == Qnil) param_value = param_value_tmp; else param_value = rb_obj_as_string(param_value_tmp); param_format = rb_hash_aref(param, sym_format); } else { param_type = INT2NUM(0); if(param == Qnil) param_value = param; else param_value = rb_obj_as_string(param); param_format = INT2NUM(0); } if(param_type == Qnil) paramTypes[i] = 0; else paramTypes[i] = NUM2INT(param_type); if(param_value == Qnil) { paramValues[i] = NULL; paramLengths[i] = 0; } else { Check_Type(param_value, T_STRING); /* make sure param_value doesn't get freed by the GC */ rb_ary_push(gc_array, param_value); paramValues[i] = StringValuePtr(param_value); paramLengths[i] = RSTRING_LEN(param_value); } if(param_format == Qnil) paramFormats[i] = 0; else paramFormats[i] = NUM2INT(param_format); } result = PQsendQueryParams(conn, StringValuePtr(command), nParams, paramTypes, (const char * const *)paramValues, paramLengths, paramFormats, resultFormat); rb_gc_unregister_address(&gc_array); xfree(paramTypes); xfree(paramValues); xfree(paramLengths); xfree(paramFormats); if(result == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
Execute prepared named statement specified by statement_name asynchronously, and returns immediately. On failure, it raises a PGError exception.
params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:
a hash of the form: {:value => String (value of bind parameter) :format => Fixnum (0 for text, 1 for binary) } or, it may be a String. If it is a string, that is equivalent to the hash: { :value => <string value>, :format => 0 }
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.
The optional result_format should be 0 for text results, 1 for binary.
static VALUE pgconn_send_query_prepared(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); int result; VALUE name, params, in_res_fmt; VALUE param, param_value, param_format; VALUE param_value_tmp; VALUE sym_value, sym_format; VALUE gc_array; VALUE error; int i = 0; int nParams; char ** paramValues; int *paramLengths; int *paramFormats; int resultFormat; rb_scan_args(argc, argv, "12", &name, ¶ms, &in_res_fmt); Check_Type(name, T_STRING); if(NIL_P(params)) { params = rb_ary_new2(0); resultFormat = 0; } else { Check_Type(params, T_ARRAY); } if(NIL_P(in_res_fmt)) { resultFormat = 0; } else { resultFormat = NUM2INT(in_res_fmt); } gc_array = rb_ary_new(); rb_gc_register_address(&gc_array); sym_value = ID2SYM(rb_intern("value")); sym_format = ID2SYM(rb_intern("format")); nParams = RARRAY_LEN(params); paramValues = ALLOC_N(char *, nParams); paramLengths = ALLOC_N(int, nParams); paramFormats = ALLOC_N(int, nParams); for(i = 0; i < nParams; i++) { param = rb_ary_entry(params, i); if (TYPE(param) == T_HASH) { param_value_tmp = rb_hash_aref(param, sym_value); if(param_value_tmp == Qnil) param_value = param_value_tmp; else param_value = rb_obj_as_string(param_value_tmp); param_format = rb_hash_aref(param, sym_format); } else { if(param == Qnil) param_value = param; else param_value = rb_obj_as_string(param); param_format = INT2NUM(0); } if(param_value == Qnil) { paramValues[i] = NULL; paramLengths[i] = 0; } else { Check_Type(param_value, T_STRING); /* make sure param_value doesn't get freed by the GC */ rb_ary_push(gc_array, param_value); paramValues[i] = StringValuePtr(param_value); paramLengths[i] = RSTRING_LEN(param_value); } if(param_format == Qnil) paramFormats[i] = 0; else paramFormats[i] = NUM2INT(param_format); } result = PQsendQueryPrepared(conn, StringValuePtr(name), nParams, (const char * const *)paramValues, paramLengths, paramFormats, resultFormat); rb_gc_unregister_address(&gc_array); xfree(paramValues); xfree(paramLengths); xfree(paramFormats); if(result == 0) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
The number is formed by converting the major, minor, and revision numbers into two-decimal-digit numbers and appending them together. For example, version 7.4.2 will be returned as 70402, and version 8.1 will be returned as 80100 (leading zeroes are not shown). Zero is returned if the connection is bad.
static VALUE pgconn_server_version(VALUE self) { return INT2NUM(PQserverVersion(get_pgconn(self))); }
Sets the client encoding to the encoding String.
static VALUE pgconn_set_client_encoding(VALUE self, VALUE str) { Check_Type(str, T_STRING); if ((PQsetClientEncoding(get_pgconn(self), StringValuePtr(str))) == -1){ rb_raise(rb_ePGError, "invalid encoding name: %s",StringValuePtr(str)); } return Qnil; }
Sets connection’s verbosity to verbosity and returns the previous setting. Available settings are:
static VALUE pgconn_set_error_verbosity(VALUE self, VALUE in_verbosity) { PGconn *conn = get_pgconn(self); PGVerbosity verbosity = NUM2INT(in_verbosity); return INT2FIX(PQsetErrorVerbosity(conn, verbosity)); }
Notice and warning messages generated by the server are not returned by the query execution functions, since they do not imply failure of the query. Instead they are passed to a notice handling function, and execution continues normally after the handler returns. The default notice handling function prints the message on stderr, but the application can override this behavior by supplying its own handling function.
This function takes a new block to act as the handler, which should accept a single parameter that will be a PGresult object, and returns the Proc object previously set, or nil if it was previously the default.
If you pass no arguments, it will reset the handler to the default.
static VALUE pgconn_set_notice_processor(VALUE self) { VALUE proc, old_proc; PGconn *conn = get_pgconn(self); /* If default_notice_processor is unset, assume that the current * notice processor is the default, and save it to a global variable. * This should not be a problem because the default processor is * always the same, so won't vary among connections. */ if(default_notice_processor == NULL) default_notice_processor = PQsetNoticeProcessor(conn, NULL, NULL); old_proc = rb_iv_get(self, "@notice_processor"); if( rb_block_given_p() ) { proc = rb_block_proc(); PQsetNoticeProcessor(conn, notice_processor_proxy, (void *)self); } else { /* if no block is given, set back to default */ proc = Qnil; PQsetNoticeProcessor(conn, default_notice_processor, NULL); } rb_iv_set(self, "@notice_processor", proc); return old_proc; }
Notice and warning messages generated by the server are not returned by the query execution functions, since they do not imply failure of the query. Instead they are passed to a notice handling function, and execution continues normally after the handler returns. The default notice handling function prints the message on stderr, but the application can override this behavior by supplying its own handling function.
This function takes a new block to act as the handler, which should accept a single parameter that will be a PGresult object, and returns the Proc object previously set, or nil if it was previously the default.
If you pass no arguments, it will reset the handler to the default.
static VALUE pgconn_set_notice_receiver(VALUE self) { VALUE proc, old_proc; PGconn *conn = get_pgconn(self); /* If default_notice_receiver is unset, assume that the current * notice receiver is the default, and save it to a global variable. * This should not be a problem because the default receiver is * always the same, so won't vary among connections. */ if(default_notice_receiver == NULL) default_notice_receiver = PQsetNoticeReceiver(conn, NULL, NULL); old_proc = rb_iv_get(self, "@notice_receiver"); if( rb_block_given_p() ) { proc = rb_block_proc(); PQsetNoticeReceiver(conn, notice_receiver_proxy, (void *)self); } else { /* if no block is given, set back to default */ proc = Qnil; PQsetNoticeReceiver(conn, default_notice_receiver, NULL); } rb_iv_set(self, "@notice_receiver", proc); return old_proc; }
Sets the nonblocking status of the connection. In the blocking state, calls to PGconn#send_query will block until the message is sent to the server, but will not wait for the query results. In the nonblocking state, calls to PGconn#send_query will return an error if the socket is not ready for writing. Note: This function does not affect PGconn#exec, because that function doesn’t return until the server has processed the query and returned the results. Returns nil.
static VALUE pgconn_setnonblocking(self, state) VALUE self, state; { int arg; VALUE error; PGconn *conn = get_pgconn(self); if(state == Qtrue) arg = 1; else if (state == Qfalse) arg = 0; else rb_raise(rb_eArgError, "Boolean value expected"); if(PQsetnonblocking(conn, arg) == -1) { error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn)); rb_iv_set(error, "@connection", self); rb_exc_raise(error); } return Qnil; }
Returns the socket’s file descriptor for this connection.
static VALUE pgconn_socket(VALUE self) { int sd; if( (sd = PQsocket(get_pgconn(self))) < 0) rb_raise(rb_ePGError, "Can't get socket descriptor"); return INT2NUM(sd); }
Returns status of connection : CONNECTION_OK or CONNECTION_BAD
static VALUE pgconn_status(VALUE self) { return INT2NUM(PQstatus(get_pgconn(self))); }
Enables tracing message passing between backend. The trace message will be written to the stream stream, which must implement a method fileno that returns a writable file descriptor.
static VALUE pgconn_trace(VALUE self, VALUE stream) { VALUE fileno; FILE *new_fp; int old_fd, new_fd; VALUE new_file; if(rb_respond_to(stream,rb_intern("fileno")) == Qfalse) rb_raise(rb_eArgError, "stream does not respond to method: fileno"); fileno = rb_funcall(stream, rb_intern("fileno"), 0); if(fileno == Qnil) rb_raise(rb_eArgError, "can't get file descriptor from stream"); /* Duplicate the file descriptor and re-open * it. Then, make it into a ruby File object * and assign it to an instance variable. * This prevents a problem when the File * object passed to this function is closed * before the connection object is. */ old_fd = NUM2INT(fileno); new_fd = dup(old_fd); new_fp = fdopen(new_fd, "w"); if(new_fp == NULL) rb_raise(rb_eArgError, "stream is not writable"); new_file = rb_funcall(rb_cIO, rb_intern("new"), 1, INT2NUM(new_fd)); rb_iv_set(self, "@trace_stream", new_file); PQtrace(get_pgconn(self), new_fp); return Qnil; }
Executes a BEGIN at the start of the block, and a COMMIT at the end of the block, or ROLLBACK if any exception occurs.
static VALUE pgconn_transaction(VALUE self) { PGconn *conn = get_pgconn(self); PGresult *result; VALUE rb_pgresult; int status; if (rb_block_given_p()) { result = PQexec(conn, "BEGIN"); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); rb_protect(rb_yield, self, &status); if(status == 0) { result = PQexec(conn, "COMMIT"); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); } else { /* exception occurred, ROLLBACK and re-raise */ result = PQexec(conn, "ROLLBACK"); rb_pgresult = new_pgresult(result, conn); pgresult_check(self, rb_pgresult); rb_jump_tag(status); } } else { /* no block supplied? */ rb_raise(rb_eArgError, "Must supply block for PGconn#transaction"); } return Qnil; }
returns one of the following statuses:
PQTRANS_IDLE = 0 (connection idle) PQTRANS_ACTIVE = 1 (command in progress) PQTRANS_INTRANS = 2 (idle, within transaction block) PQTRANS_INERROR = 3 (idle, within failed transaction) PQTRANS_UNKNOWN = 4 (cannot determine status)
static VALUE pgconn_transaction_status(VALUE self) { return INT2NUM(PQtransactionStatus(get_pgconn(self))); }
Returns the connected pgtty. (Obsolete)
static VALUE pgconn_tty(VALUE self) { char *tty = PQtty(get_pgconn(self)); if (!tty) return Qnil; return rb_tainted_str_new2(tty); }
Converts an escaped string representation of binary data into binary data — the reverse of #. This is needed when retrieving bytea data in text format, but not when retrieving it in binary format.
static VALUE pgconn_s_unescape_bytea(VALUE self, VALUE str) { unsigned char *from, *to; size_t to_len; VALUE ret; Check_Type(str, T_STRING); from = (unsigned char*)StringValuePtr(str); to = PQunescapeBytea(from, &to_len); ret = rb_str_new((char*)to, to_len); OBJ_INFECT(ret, str); PQfreemem(to); return ret; }
Disables the message tracing.
static VALUE pgconn_untrace(VALUE self) { VALUE trace_stream; PQuntrace(get_pgconn(self)); trace_stream = rb_iv_get(self, "@trace_stream"); rb_funcall(trace_stream, rb_intern("close"), 0); rb_iv_set(self, "@trace_stream", Qnil); return Qnil; }
Returns the authenticated user name.
static VALUE pgconn_user(VALUE self) { char *user = PQuser(get_pgconn(self)); if (!user) return Qnil; return rb_tainted_str_new2(user); }
Blocks while waiting for notification(s), or until the optional timeout is reached, whichever comes first. timeout is measured in seconds and can be fractional.
Returns nil if timeout is reached, the name of the NOTIFY event otherwise. If used in block form, passes the name of the NOTIFY event and the generating pid into the block.
static VALUE pgconn_wait_for_notify(int argc, VALUE *argv, VALUE self) { PGconn *conn = get_pgconn(self); PGnotify *notify; int sd = PQsocket(conn); int ret; struct timeval timeout; struct timeval *ptimeout = NULL; VALUE timeout_in, relname = Qnil, be_pid = Qnil; double timeout_sec; fd_set sd_rset; if (sd < 0) rb_bug("PQsocket(conn): couldn't fetch the connection's socket!"); if (rb_scan_args(argc, argv, "01", &timeout_in) == 1) { timeout_sec = NUM2DBL(timeout_in); timeout.tv_sec = (long)timeout_sec; timeout.tv_usec = (long)((timeout_sec - (long)timeout_sec) * 1e6); ptimeout = &timeout; } FD_ZERO(&sd_rset); FD_SET(sd, &sd_rset); ret = rb_thread_select(sd+1, &sd_rset, NULL, NULL, ptimeout); if (ret == 0) { return Qnil; } else if (ret < 0) { rb_sys_fail(0); } if ( (ret = PQconsumeInput(conn)) != 1 ) { rb_raise(rb_ePGError, "PQconsumeInput == %d: %s", ret, PQerrorMessage(conn)); } while ((notify = PQnotifies(conn)) != NULL) { relname = rb_tainted_str_new2(notify->relname); be_pid = INT2NUM(notify->be_pid); PQfreemem(notify); } if (rb_block_given_p()) rb_yield( rb_ary_new3(2, relname, be_pid) ); return relname; }
Disabled; run with --debug to generate this.
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