121 lines
3.0 KiB
Plaintext
121 lines
3.0 KiB
Plaintext
==================================================================
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Name
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dblink -- Returns a set from a remote database
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Synopsis
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dblink(text connstr, text sql [, bool fail_on_error])
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dblink(text connname, text sql [, bool fail_on_error])
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dblink(text sql [, bool fail_on_error])
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Inputs
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connname
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connstr
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If two arguments are present, the first is first assumed to be a specific
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connection name to use. If the name is not found, the argument is then
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assumed to be a valid connection string, of standard libpq format,
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e.g.: "hostaddr=127.0.0.1 dbname=mydb user=postgres password=mypasswd"
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If only one argument is used, then the unnamed connection is used.
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sql
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sql statement that you wish to execute on the remote host
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e.g. "select * from pg_class"
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fail_on_error
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If true (default when not present) then an ERROR thrown on the remote side
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of the connection causes an ERROR to also be thrown locally. If false, the
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remote ERROR is locally treated as a NOTICE, and no rows are returned.
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Outputs
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Returns setof record
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Example usage
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select * from dblink('dbname=postgres','select proname, prosrc from pg_proc')
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as t1(proname name, prosrc text) where proname like 'bytea%';
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proname | prosrc
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------------+------------
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byteacat | byteacat
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byteaeq | byteaeq
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bytealt | bytealt
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byteale | byteale
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byteagt | byteagt
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byteage | byteage
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byteane | byteane
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byteacmp | byteacmp
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bytealike | bytealike
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byteanlike | byteanlike
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byteain | byteain
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byteaout | byteaout
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(12 rows)
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select dblink_connect('dbname=postgres');
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dblink_connect
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----------------
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OK
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(1 row)
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select * from dblink('select proname, prosrc from pg_proc')
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as t1(proname name, prosrc text) where proname like 'bytea%';
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proname | prosrc
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------------+------------
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byteacat | byteacat
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byteaeq | byteaeq
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bytealt | bytealt
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byteale | byteale
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byteagt | byteagt
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byteage | byteage
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byteane | byteane
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byteacmp | byteacmp
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bytealike | bytealike
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byteanlike | byteanlike
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byteain | byteain
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byteaout | byteaout
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(12 rows)
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select dblink_connect('myconn','dbname=regression');
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dblink_connect
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----------------
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OK
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(1 row)
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select * from dblink('myconn','select proname, prosrc from pg_proc')
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as t1(proname name, prosrc text) where proname like 'bytea%';
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proname | prosrc
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------------+------------
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bytearecv | bytearecv
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byteasend | byteasend
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byteale | byteale
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byteagt | byteagt
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byteage | byteage
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byteane | byteane
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byteacmp | byteacmp
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bytealike | bytealike
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byteanlike | byteanlike
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byteacat | byteacat
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byteaeq | byteaeq
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bytealt | bytealt
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byteain | byteain
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byteaout | byteaout
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(14 rows)
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==================================================================
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A more convenient way to use dblink may be to create a view:
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create view myremote_pg_proc as
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select *
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from dblink('dbname=postgres','select proname, prosrc from pg_proc')
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as t1(proname name, prosrc text);
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Then you can simply write:
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select * from myremote_pg_proc where proname like 'bytea%';
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