dblink_open(3) [centos man page]
DBLINK_OPEN(3) PostgreSQL 9.2.7 Documentation DBLINK_OPEN(3) NAME
dblink_open - opens a cursor in a remote database SYNOPSIS
dblink_open(text cursorname, text sql [, bool fail_on_error]) returns text dblink_open(text connname, text cursorname, text sql [, bool fail_on_error]) returns text DESCRIPTION
dblink_open() opens a cursor in a remote database. The cursor can subsequently be manipulated with dblink_fetch() and dblink_close(). ARGUMENTS
conname Name of the connection to use; omit this parameter to use the unnamed connection. cursorname The name to assign to this cursor. sql The SELECT statement that you wish to execute in the remote database, for example select * from pg_class. fail_on_error If true (the default when omitted) then an error thrown on the remote side of the connection causes an error to also be thrown locally. If false, the remote error is locally reported as a NOTICE, and the function's return value is set to ERROR. RETURN VALUE
Returns status, either OK or ERROR. NOTES
Since a cursor can only persist within a transaction, dblink_open starts an explicit transaction block (BEGIN) on the remote side, if the remote side was not already within a transaction. This transaction will be closed again when the matching dblink_close is executed. Note that if you use dblink_exec to change data between dblink_open and dblink_close, and then an error occurs or you use dblink_disconnect before dblink_close, your change will be lost because the transaction will be aborted. EXAMPLES
SELECT dblink_connect('dbname=postgres'); dblink_connect ---------------- OK (1 row) SELECT dblink_open('foo', 'select proname, prosrc from pg_proc'); dblink_open ------------- OK (1 row) PostgreSQL 9.2.7 2014-02-17 DBLINK_OPEN(3)
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DBLINK_EXEC(3) PostgreSQL 9.2.7 Documentation DBLINK_EXEC(3) NAME
dblink_exec - executes a command in a remote database SYNOPSIS
dblink_exec(text connname, text sql [, bool fail_on_error]) returns text dblink_exec(text connstr, text sql [, bool fail_on_error]) returns text dblink_exec(text sql [, bool fail_on_error]) returns text DESCRIPTION
dblink_exec executes a command (that is, any SQL statement that doesn't return rows) in a remote database. When two text arguments are given, the first one is first looked up as a persistent connection's name; if found, the command is executed on that connection. If not found, the first argument is treated as a connection info string as for dblink_connect, and the indicated connection is made just for the duration of this command. ARGUMENTS
conname Name of the connection to use; omit this parameter to use the unnamed connection. connstr A connection info string, as previously described for dblink_connect. sql The SQL command that you wish to execute in the remote database, for example insert into foo values(0,'a','{"a0","b0","c0"}'). fail_on_error If true (the default when omitted) then an error thrown on the remote side of the connection causes an error to also be thrown locally. If false, the remote error is locally reported as a NOTICE, and the function's return value is set to ERROR. RETURN VALUE
Returns status, either the command's status string or ERROR. EXAMPLES
SELECT dblink_connect('dbname=dblink_test_standby'); dblink_connect ---------------- OK (1 row) SELECT dblink_exec('insert into foo values(21,''z'',''{"a0","b0","c0"}'');'); dblink_exec ----------------- INSERT 943366 1 (1 row) SELECT dblink_connect('myconn', 'dbname=regression'); dblink_connect ---------------- OK (1 row) SELECT dblink_exec('myconn', 'insert into foo values(21,''z'',''{"a0","b0","c0"}'');'); dblink_exec ------------------ INSERT 6432584 1 (1 row) SELECT dblink_exec('myconn', 'insert into pg_class values (''foo'')',false); NOTICE: sql error DETAIL: ERROR: null value in column "relnamespace" violates not-null constraint dblink_exec ------------- ERROR (1 row) PostgreSQL 9.2.7 2014-02-17 DBLINK_EXEC(3)