postgresql/contrib/dblink/sql/dblink.sql
Tom Lane 8a3b6772ae Fix contrib/dblink to handle inconsistent DateStyle/IntervalStyle safely.
If the remote database's settings of these GUCs are different from ours,
ambiguous datetime values may be read incorrectly.  To fix, temporarily
adopt the remote server's settings while we ingest a query result.

This is not a complete fix, since it doesn't do anything about ambiguous
values in commands sent to the remote server; but there seems little we
can do about that end of it given dblink's entirely textual API for
transmitted commands.

Back-patch to 9.2.  The hazard exists in all versions, but this patch
would need more work to apply before 9.2.  Given the lack of field
complaints about this issue, it doesn't seem worth the effort at present.

Daniel Farina and Tom Lane
2013-03-22 15:22:54 -04:00

525 lines
17 KiB
PL/PgSQL

CREATE EXTENSION dblink;
CREATE TABLE foo(f1 int, f2 text, f3 text[], primary key (f1,f2));
INSERT INTO foo VALUES (0,'a','{"a0","b0","c0"}');
INSERT INTO foo VALUES (1,'b','{"a1","b1","c1"}');
INSERT INTO foo VALUES (2,'c','{"a2","b2","c2"}');
INSERT INTO foo VALUES (3,'d','{"a3","b3","c3"}');
INSERT INTO foo VALUES (4,'e','{"a4","b4","c4"}');
INSERT INTO foo VALUES (5,'f','{"a5","b5","c5"}');
INSERT INTO foo VALUES (6,'g','{"a6","b6","c6"}');
INSERT INTO foo VALUES (7,'h','{"a7","b7","c7"}');
INSERT INTO foo VALUES (8,'i','{"a8","b8","c8"}');
INSERT INTO foo VALUES (9,'j','{"a9","b9","c9"}');
-- misc utilities
-- list the primary key fields
SELECT *
FROM dblink_get_pkey('foo');
-- build an insert statement based on a local tuple,
-- replacing the primary key values with new ones
SELECT dblink_build_sql_insert('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
-- too many pk fields, should fail
SELECT dblink_build_sql_insert('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
-- build an update statement based on a local tuple,
-- replacing the primary key values with new ones
SELECT dblink_build_sql_update('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
-- too many pk fields, should fail
SELECT dblink_build_sql_update('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
-- build a delete statement based on a local tuple,
SELECT dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');
-- too many pk fields, should fail
SELECT dblink_build_sql_delete('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}');
-- retest using a quoted and schema qualified table
CREATE SCHEMA "MySchema";
CREATE TABLE "MySchema"."Foo"(f1 int, f2 text, f3 text[], primary key (f1,f2));
INSERT INTO "MySchema"."Foo" VALUES (0,'a','{"a0","b0","c0"}');
-- list the primary key fields
SELECT *
FROM dblink_get_pkey('"MySchema"."Foo"');
-- build an insert statement based on a local tuple,
-- replacing the primary key values with new ones
SELECT dblink_build_sql_insert('"MySchema"."Foo"','1 2',2,'{"0", "a"}','{"99", "xyz"}');
-- build an update statement based on a local tuple,
-- replacing the primary key values with new ones
SELECT dblink_build_sql_update('"MySchema"."Foo"','1 2',2,'{"0", "a"}','{"99", "xyz"}');
-- build a delete statement based on a local tuple,
SELECT dblink_build_sql_delete('"MySchema"."Foo"','1 2',2,'{"0", "a"}');
-- regular old dblink
SELECT *
FROM dblink('dbname=contrib_regression','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- should generate "connection not available" error
SELECT *
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- create a persistent connection
SELECT dblink_connect('dbname=contrib_regression');
-- use the persistent connection
SELECT *
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- open a cursor with bad SQL and fail_on_error set to false
SELECT dblink_open('rmt_foo_cursor','SELECT * FROM foobar',false);
-- reset remote transaction state
SELECT dblink_exec('ABORT');
-- open a cursor
SELECT dblink_open('rmt_foo_cursor','SELECT * FROM foo');
-- close the cursor
SELECT dblink_close('rmt_foo_cursor',false);
-- open the cursor again
SELECT dblink_open('rmt_foo_cursor','SELECT * FROM foo');
-- fetch some data
SELECT *
FROM dblink_fetch('rmt_foo_cursor',4) AS t(a int, b text, c text[]);
SELECT *
FROM dblink_fetch('rmt_foo_cursor',4) AS t(a int, b text, c text[]);
-- this one only finds two rows left
SELECT *
FROM dblink_fetch('rmt_foo_cursor',4) AS t(a int, b text, c text[]);
-- intentionally botch a fetch
SELECT *
FROM dblink_fetch('rmt_foobar_cursor',4,false) AS t(a int, b text, c text[]);
-- reset remote transaction state
SELECT dblink_exec('ABORT');
-- close the wrong cursor
SELECT dblink_close('rmt_foobar_cursor',false);
-- should generate 'cursor "rmt_foo_cursor" not found' error
SELECT *
FROM dblink_fetch('rmt_foo_cursor',4) AS t(a int, b text, c text[]);
-- this time, 'cursor "rmt_foo_cursor" not found' as a notice
SELECT *
FROM dblink_fetch('rmt_foo_cursor',4,false) AS t(a int, b text, c text[]);
-- close the persistent connection
SELECT dblink_disconnect();
-- should generate "connection not available" error
SELECT *
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- put more data into our slave table, first using arbitrary connection syntax
-- but truncate the actual return value so we can use diff to check for success
SELECT substr(dblink_exec('dbname=contrib_regression','INSERT INTO foo VALUES(10,''k'',''{"a10","b10","c10"}'')'),1,6);
-- create a persistent connection
SELECT dblink_connect('dbname=contrib_regression');
-- put more data into our slave table, using persistent connection syntax
-- but truncate the actual return value so we can use diff to check for success
SELECT substr(dblink_exec('INSERT INTO foo VALUES(11,''l'',''{"a11","b11","c11"}'')'),1,6);
-- let's see it
SELECT *
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[]);
-- bad remote select
SELECT *
FROM dblink('SELECT * FROM foobar',false) AS t(a int, b text, c text[]);
-- change some data
SELECT dblink_exec('UPDATE foo SET f3[2] = ''b99'' WHERE f1 = 11');
-- let's see it
SELECT *
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE a = 11;
-- botch a change to some other data
SELECT dblink_exec('UPDATE foobar SET f3[2] = ''b99'' WHERE f1 = 11',false);
-- delete some data
SELECT dblink_exec('DELETE FROM foo WHERE f1 = 11');
-- let's see it
SELECT *
FROM dblink('SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE a = 11;
-- close the persistent connection
SELECT dblink_disconnect();
--
-- tests for the new named persistent connection syntax
--
-- should generate "missing "=" after "myconn" in connection info string" error
SELECT *
FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- create a named persistent connection
SELECT dblink_connect('myconn','dbname=contrib_regression');
-- use the named persistent connection
SELECT *
FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- use the named persistent connection, but get it wrong
SELECT *
FROM dblink('myconn','SELECT * FROM foobar',false) AS t(a int, b text, c text[])
WHERE t.a > 7;
-- create a second named persistent connection
-- should error with "duplicate connection name"
SELECT dblink_connect('myconn','dbname=contrib_regression');
-- create a second named persistent connection with a new name
SELECT dblink_connect('myconn2','dbname=contrib_regression');
-- use the second named persistent connection
SELECT *
FROM dblink('myconn2','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- close the second named persistent connection
SELECT dblink_disconnect('myconn2');
-- open a cursor incorrectly
SELECT dblink_open('myconn','rmt_foo_cursor','SELECT * FROM foobar',false);
-- reset remote transaction state
SELECT dblink_exec('myconn','ABORT');
-- test opening cursor in a transaction
SELECT dblink_exec('myconn','BEGIN');
-- an open transaction will prevent dblink_open() from opening its own
SELECT dblink_open('myconn','rmt_foo_cursor','SELECT * FROM foo');
-- this should not commit the transaction because the client opened it
SELECT dblink_close('myconn','rmt_foo_cursor');
-- this should succeed because we have an open transaction
SELECT dblink_exec('myconn','DECLARE xact_test CURSOR FOR SELECT * FROM foo');
-- commit remote transaction
SELECT dblink_exec('myconn','COMMIT');
-- test automatic transactions for multiple cursor opens
SELECT dblink_open('myconn','rmt_foo_cursor','SELECT * FROM foo');
-- the second cursor
SELECT dblink_open('myconn','rmt_foo_cursor2','SELECT * FROM foo');
-- this should not commit the transaction
SELECT dblink_close('myconn','rmt_foo_cursor2');
-- this should succeed because we have an open transaction
SELECT dblink_exec('myconn','DECLARE xact_test CURSOR FOR SELECT * FROM foo');
-- this should commit the transaction
SELECT dblink_close('myconn','rmt_foo_cursor');
-- this should fail because there is no open transaction
SELECT dblink_exec('myconn','DECLARE xact_test CURSOR FOR SELECT * FROM foo');
-- reset remote transaction state
SELECT dblink_exec('myconn','ABORT');
-- open a cursor
SELECT dblink_open('myconn','rmt_foo_cursor','SELECT * FROM foo');
-- fetch some data
SELECT *
FROM dblink_fetch('myconn','rmt_foo_cursor',4) AS t(a int, b text, c text[]);
SELECT *
FROM dblink_fetch('myconn','rmt_foo_cursor',4) AS t(a int, b text, c text[]);
-- this one only finds three rows left
SELECT *
FROM dblink_fetch('myconn','rmt_foo_cursor',4) AS t(a int, b text, c text[]);
-- fetch some data incorrectly
SELECT *
FROM dblink_fetch('myconn','rmt_foobar_cursor',4,false) AS t(a int, b text, c text[]);
-- reset remote transaction state
SELECT dblink_exec('myconn','ABORT');
-- should generate 'cursor "rmt_foo_cursor" not found' error
SELECT *
FROM dblink_fetch('myconn','rmt_foo_cursor',4) AS t(a int, b text, c text[]);
-- close the named persistent connection
SELECT dblink_disconnect('myconn');
-- should generate "missing "=" after "myconn" in connection info string" error
SELECT *
FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE t.a > 7;
-- create a named persistent connection
SELECT dblink_connect('myconn','dbname=contrib_regression');
-- put more data into our slave table, using named persistent connection syntax
-- but truncate the actual return value so we can use diff to check for success
SELECT substr(dblink_exec('myconn','INSERT INTO foo VALUES(11,''l'',''{"a11","b11","c11"}'')'),1,6);
-- let's see it
SELECT *
FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[]);
-- change some data
SELECT dblink_exec('myconn','UPDATE foo SET f3[2] = ''b99'' WHERE f1 = 11');
-- let's see it
SELECT *
FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE a = 11;
-- delete some data
SELECT dblink_exec('myconn','DELETE FROM foo WHERE f1 = 11');
-- let's see it
SELECT *
FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[])
WHERE a = 11;
-- close the named persistent connection
SELECT dblink_disconnect('myconn');
-- close the named persistent connection again
-- should get 'connection "myconn" not available' error
SELECT dblink_disconnect('myconn');
-- test asynchronous queries
SELECT dblink_connect('dtest1', 'dbname=contrib_regression');
SELECT * from
dblink_send_query('dtest1', 'select * from foo where f1 < 3') as t1;
SELECT dblink_connect('dtest2', 'dbname=contrib_regression');
SELECT * from
dblink_send_query('dtest2', 'select * from foo where f1 > 2 and f1 < 7') as t1;
SELECT dblink_connect('dtest3', 'dbname=contrib_regression');
SELECT * from
dblink_send_query('dtest3', 'select * from foo where f1 > 6') as t1;
CREATE TEMPORARY TABLE result AS
(SELECT * from dblink_get_result('dtest1') as t1(f1 int, f2 text, f3 text[]))
UNION
(SELECT * from dblink_get_result('dtest2') as t2(f1 int, f2 text, f3 text[]))
UNION
(SELECT * from dblink_get_result('dtest3') as t3(f1 int, f2 text, f3 text[]))
ORDER by f1;
-- dblink_get_connections returns an array with elements in a machine-dependent
-- ordering, so we must resort to unnesting and sorting for a stable result
create function unnest(anyarray) returns setof anyelement
language sql strict immutable as $$
select $1[i] from generate_series(array_lower($1,1), array_upper($1,1)) as i
$$;
SELECT * FROM unnest(dblink_get_connections()) ORDER BY 1;
SELECT dblink_is_busy('dtest1');
SELECT dblink_disconnect('dtest1');
SELECT dblink_disconnect('dtest2');
SELECT dblink_disconnect('dtest3');
SELECT * from result;
SELECT dblink_connect('dtest1', 'dbname=contrib_regression');
SELECT * from
dblink_send_query('dtest1', 'select * from foo where f1 < 3') as t1;
SELECT dblink_cancel_query('dtest1');
SELECT dblink_error_message('dtest1');
SELECT dblink_disconnect('dtest1');
-- test foreign data wrapper functionality
CREATE USER dblink_regression_test;
CREATE SERVER fdtest FOREIGN DATA WRAPPER dblink_fdw
OPTIONS (dbname 'contrib_regression');
CREATE USER MAPPING FOR public SERVER fdtest
OPTIONS (server 'localhost'); -- fail, can't specify server here
CREATE USER MAPPING FOR public SERVER fdtest;
GRANT USAGE ON FOREIGN SERVER fdtest TO dblink_regression_test;
GRANT EXECUTE ON FUNCTION dblink_connect_u(text, text) TO dblink_regression_test;
\set ORIGINAL_USER :USER
\c - dblink_regression_test
-- should fail
SELECT dblink_connect('myconn', 'fdtest');
-- should succeed
SELECT dblink_connect_u('myconn', 'fdtest');
SELECT * FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[]);
\c - :ORIGINAL_USER
REVOKE USAGE ON FOREIGN SERVER fdtest FROM dblink_regression_test;
REVOKE EXECUTE ON FUNCTION dblink_connect_u(text, text) FROM dblink_regression_test;
DROP USER dblink_regression_test;
DROP USER MAPPING FOR public SERVER fdtest;
DROP SERVER fdtest;
-- test asynchronous notifications
SELECT dblink_connect('dbname=contrib_regression');
--should return listen
SELECT dblink_exec('LISTEN regression');
--should return listen
SELECT dblink_exec('LISTEN foobar');
SELECT dblink_exec('NOTIFY regression');
SELECT dblink_exec('NOTIFY foobar');
SELECT notify_name, be_pid = (select t.be_pid from dblink('select pg_backend_pid()') as t(be_pid int)) AS is_self_notify, extra from dblink_get_notify();
SELECT * from dblink_get_notify();
SELECT dblink_disconnect();
-- test dropped columns in dblink_build_sql_insert, dblink_build_sql_update
CREATE TEMP TABLE test_dropped
(
col1 INT NOT NULL DEFAULT 111,
id SERIAL PRIMARY KEY,
col2 INT NOT NULL DEFAULT 112,
col2b INT NOT NULL DEFAULT 113
);
INSERT INTO test_dropped VALUES(default);
ALTER TABLE test_dropped
DROP COLUMN col1,
DROP COLUMN col2,
ADD COLUMN col3 VARCHAR(10) NOT NULL DEFAULT 'foo',
ADD COLUMN col4 INT NOT NULL DEFAULT 42;
SELECT dblink_build_sql_insert('test_dropped', '1', 1,
ARRAY['1'::TEXT], ARRAY['2'::TEXT]);
SELECT dblink_build_sql_update('test_dropped', '1', 1,
ARRAY['1'::TEXT], ARRAY['2'::TEXT]);
SELECT dblink_build_sql_delete('test_dropped', '1', 1,
ARRAY['2'::TEXT]);
-- test local mimicry of remote GUC values that affect datatype I/O
SET datestyle = ISO, MDY;
SET intervalstyle = postgres;
SET timezone = UTC;
SELECT dblink_connect('myconn','dbname=contrib_regression');
SELECT dblink_exec('myconn', 'SET datestyle = GERMAN, DMY;');
-- single row synchronous case
SELECT *
FROM dblink('myconn',
'SELECT * FROM (VALUES (''12.03.2013 00:00:00+00'')) t')
AS t(a timestamptz);
-- multi-row synchronous case
SELECT *
FROM dblink('myconn',
'SELECT * FROM
(VALUES (''12.03.2013 00:00:00+00''),
(''12.03.2013 00:00:00+00'')) t')
AS t(a timestamptz);
-- single-row asynchronous case
SELECT *
FROM dblink_send_query('myconn',
'SELECT * FROM
(VALUES (''12.03.2013 00:00:00+00'')) t');
CREATE TEMPORARY TABLE result AS
(SELECT * from dblink_get_result('myconn') as t(t timestamptz))
UNION ALL
(SELECT * from dblink_get_result('myconn') as t(t timestamptz));
SELECT * FROM result;
DROP TABLE result;
-- multi-row asynchronous case
SELECT *
FROM dblink_send_query('myconn',
'SELECT * FROM
(VALUES (''12.03.2013 00:00:00+00''),
(''12.03.2013 00:00:00+00'')) t');
CREATE TEMPORARY TABLE result AS
(SELECT * from dblink_get_result('myconn') as t(t timestamptz))
UNION ALL
(SELECT * from dblink_get_result('myconn') as t(t timestamptz))
UNION ALL
(SELECT * from dblink_get_result('myconn') as t(t timestamptz));
SELECT * FROM result;
DROP TABLE result;
-- Try an ambiguous interval
SELECT dblink_exec('myconn', 'SET intervalstyle = sql_standard;');
SELECT *
FROM dblink('myconn',
'SELECT * FROM (VALUES (''-1 2:03:04'')) i')
AS i(i interval);
-- Try swapping to another format to ensure the GUCs are tracked
-- properly through a change.
CREATE TEMPORARY TABLE result (t timestamptz);
SELECT dblink_exec('myconn', 'SET datestyle = ISO, MDY;');
INSERT INTO result
SELECT *
FROM dblink('myconn',
'SELECT * FROM (VALUES (''03.12.2013 00:00:00+00'')) t')
AS t(a timestamptz);
SELECT dblink_exec('myconn', 'SET datestyle = GERMAN, DMY;');
INSERT INTO result
SELECT *
FROM dblink('myconn',
'SELECT * FROM (VALUES (''12.03.2013 00:00:00+00'')) t')
AS t(a timestamptz);
SELECT * FROM result;
DROP TABLE result;
-- Check error throwing in dblink_fetch
SELECT dblink_open('myconn','error_cursor',
'SELECT * FROM (VALUES (''1''), (''not an int'')) AS t(text);');
SELECT *
FROM dblink_fetch('myconn','error_cursor', 1) AS t(i int);
SELECT *
FROM dblink_fetch('myconn','error_cursor', 1) AS t(i int);
-- Make sure that the local settings have retained their values in spite
-- of shenanigans on the connection.
SHOW datestyle;
SHOW intervalstyle;
-- Clean up GUC-setting tests
SELECT dblink_disconnect('myconn');
RESET datestyle;
RESET intervalstyle;
RESET timezone;