rangefuncs.out

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

INSERT INTO foorescan values(5007,4,'abc.5007.4');
INSERT INTO foorescan values(5008,4,'abc.5008.4');
INSERT INTO foorescan values(5009,4,'abc.5009.4');
INSERT INTO foorescan values(5000,5,'abc.5000.5');
INSERT INTO foorescan values(5001,5,'abc.5001.5');
INSERT INTO foorescan values(5002,5,'abc.5002.5');
INSERT INTO foorescan values(5003,5,'abc.5003.5');
INSERT INTO foorescan values(5004,5,'abc.5004.5');
INSERT INTO foorescan values(5005,5,'abc.5005.5');
INSERT INTO foorescan values(5006,5,'abc.5006.5');
INSERT INTO foorescan values(5007,5,'abc.5007.5');
INSERT INTO foorescan values(5008,5,'abc.5008.5');
INSERT INTO foorescan values(5009,5,'abc.5009.5');
CREATE FUNCTION foorescan(int,int) RETURNS setof foorescan AS 'SELECT * FROM foorescan WHERE fooid >= $1 and fooid < $2 ;' LANGUAGE SQL;
--invokes ExecFunctionReScan
SELECT * FROM foorescan f WHERE f.fooid IN (SELECT fooid FROM foorescan(5002,5004)) ORDER BY 1,2;
 fooid | foosubid |  fooname   
-------+----------+------------
  5002 |        1 | abc.5002.1
  5002 |        2 | abc.5002.2
  5002 |        3 | abc.5002.3
  5002 |        4 | abc.5002.4
  5002 |        5 | abc.5002.5
  5003 |        1 | abc.5003.1
  5003 |        2 | abc.5003.2
  5003 |        3 | abc.5003.3
  5003 |        4 | abc.5003.4
  5003 |        5 | abc.5003.5
(10 rows)

CREATE VIEW vw_foorescan AS SELECT * FROM foorescan(5002,5004);
--invokes ExecFunctionReScan
SELECT * FROM foorescan f WHERE f.fooid IN (SELECT fooid FROM vw_foorescan) ORDER BY 1,2;
 fooid | foosubid |  fooname   
-------+----------+------------
  5002 |        1 | abc.5002.1
  5002 |        2 | abc.5002.2
  5002 |        3 | abc.5002.3
  5002 |        4 | abc.5002.4
  5002 |        5 | abc.5002.5
  5003 |        1 | abc.5003.1
  5003 |        2 | abc.5003.2
  5003 |        3 | abc.5003.3
  5003 |        4 | abc.5003.4
  5003 |        5 | abc.5003.5
(10 rows)

CREATE TABLE barrescan (fooid int primary key);
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "barrescan_pkey" for table "barrescan"
INSERT INTO barrescan values(5003);
INSERT INTO barrescan values(5004);
INSERT INTO barrescan values(5005);
INSERT INTO barrescan values(5006);
INSERT INTO barrescan values(5007);
INSERT INTO barrescan values(5008);
CREATE FUNCTION foorescan(int) RETURNS setof foorescan AS 'SELECT * FROM foorescan WHERE fooid = $1;' LANGUAGE SQL;
--invokes ExecFunctionReScan with chgParam != NULL
SELECT f.* FROM barrescan b, foorescan f WHERE f.fooid = b.fooid AND b.fooid IN (SELECT fooid FROM foorescan(b.fooid)) ORDER BY 1,2;
 fooid | foosubid |  fooname   
-------+----------+------------
  5003 |        1 | abc.5003.1
  5003 |        2 | abc.5003.2
  5003 |        3 | abc.5003.3
  5003 |        4 | abc.5003.4
  5003 |        5 | abc.5003.5
  5004 |        1 | abc.5004.1
  5004 |        2 | abc.5004.2
  5004 |        3 | abc.5004.3
  5004 |        4 | abc.5004.4
  5004 |        5 | abc.5004.5
  5005 |        1 | abc.5005.1
  5005 |        2 | abc.5005.2
  5005 |        3 | abc.5005.3
  5005 |        4 | abc.5005.4
  5005 |        5 | abc.5005.5
  5006 |        1 | abc.5006.1
  5006 |        2 | abc.5006.2
  5006 |        3 | abc.5006.3
  5006 |        4 | abc.5006.4
  5006 |        5 | abc.5006.5
  5007 |        1 | abc.5007.1
  5007 |        2 | abc.5007.2
  5007 |        3 | abc.5007.3
  5007 |        4 | abc.5007.4
  5007 |        5 | abc.5007.5
  5008 |        1 | abc.5008.1
  5008 |        2 | abc.5008.2
  5008 |        3 | abc.5008.3
  5008 |        4 | abc.5008.4
  5008 |        5 | abc.5008.5
(30 rows)

SELECT b.fooid, max(f.foosubid) FROM barrescan b, foorescan f WHERE f.fooid = b.fooid AND b.fooid IN (SELECT fooid FROM foorescan(b.fooid)) GROUP BY b.fooid ORDER BY 1,2;
 fooid | max 
-------+-----
  5003 |   5
  5004 |   5
  5005 |   5
  5006 |   5
  5007 |   5
  5008 |   5
(6 rows)

CREATE VIEW fooview1 AS SELECT f.* FROM barrescan b, foorescan f WHERE f.fooid = b.fooid AND b.fooid IN (SELECT fooid FROM foorescan(b.fooid)) ORDER BY 1,2;
SELECT * FROM fooview1 AS fv WHERE fv.fooid = 5004;
 fooid | foosubid |  fooname   
-------+----------+------------
  5004 |        1 | abc.5004.1
  5004 |        2 | abc.5004.2
  5004 |        3 | abc.5004.3
  5004 |        4 | abc.5004.4
  5004 |        5 | abc.5004.5
(5 rows)

CREATE VIEW fooview2 AS SELECT b.fooid, max(f.foosubid) AS maxsubid FROM barrescan b, foorescan f WHERE f.fooid = b.fooid AND b.fooid IN (SELECT fooid FROM foorescan(b.fooid)) GROUP BY b.fooid ORDER BY 1,2;
SELECT * FROM fooview2 AS fv WHERE fv.maxsubid = 5;
 fooid | maxsubid 
-------+----------
  5003 |        5
  5004 |        5
  5005 |        5
  5006 |        5
  5007 |        5
  5008 |        5
(6 rows)

DROP VIEW vw_foorescan;
DROP VIEW fooview1;
DROP VIEW fooview2;
DROP FUNCTION foorescan(int,int);
DROP FUNCTION foorescan(int);
DROP TABLE foorescan;
DROP TABLE barrescan;
--
-- Test cases involving OUT parameters
--
CREATE FUNCTION foo(in f1 int, out f2 int)
AS 'select $1+1' LANGUAGE sql;
SELECT foo(42);
 foo 
-----
  43
(1 row)

SELECT * FROM foo(42);
 f2 
----
 43
(1 row)

SELECT * FROM foo(42) AS p(x);
 x  
----
 43
(1 row)

-- explicit spec of return type is OK
CREATE OR REPLACE FUNCTION foo(in f1 int, out f2 int) RETURNS int
AS 'select $1+1' LANGUAGE sql;
-- error, wrong result type
CREATE OR REPLACE FUNCTION foo(in f1 int, out f2 int) RETURNS float
AS 'select $1+1' LANGUAGE sql;
ERROR:  function result type must be integer because of OUT parameters
-- with multiple OUT params you must get a RECORD result
CREATE OR REPLACE FUNCTION foo(in f1 int, out f2 int, out f3 text) RETURNS int
AS 'select $1+1' LANGUAGE sql;
ERROR:  function result type must be record because of OUT parameters
CREATE OR REPLACE FUNCTION foo(in f1 int, out f2 int, out f3 text)
RETURNS record
AS 'select $1+1' LANGUAGE sql;
ERROR:  cannot change return type of existing function
HINT:  Use DROP FUNCTION first.
CREATE OR REPLACE FUNCTION foor(in f1 int, out f2 int, out text)
AS $$select $1-1, $1::text || 'z'$$ LANGUAGE sql;
SELECT f1, foor(f1) FROM int4_tbl;
     f1      |            foor            
-------------+----------------------------
           0 | (-1,0z)
      123456 | (123455,123456z)
     -123456 | (-123457,-123456z)
  2147483647 | (2147483646,2147483647z)
 -2147483647 | (-2147483648,-2147483647z)
(5 rows)

SELECT * FROM foor(42);
 f2 | column2 
----+---------
 41 | 42z
(1 row)

SELECT * FROM foor(42) AS p(a,b);
 a  |  b  
----+-----
 41 | 42z
(1 row)

CREATE OR REPLACE FUNCTION foob(in f1 int, inout f2 int, out text)
AS $$select $2-1, $1::text || 'z'$$ LANGUAGE sql;
SELECT f1, foob(f1, f1/2) FROM int4_tbl;
     f1      |            foob            
-------------+----------------------------
           0 | (-1,0z)
      123456 | (61727,123456z)
     -123456 | (-61729,-123456z)
  2147483647 | (1073741822,2147483647z)
 -2147483647 | (-1073741824,-2147483647z)
(5 rows)

SELECT * FROM foob(42, 99);
 f2 | column2 
----+---------
 98 | 42z
(1 row)

SELECT * FROM foob(42, 99) AS p(a,b);
 a  |  b  
----+-----
 98 | 42z
(1 row)

-- Can reference function with or without OUT params for DROP, etc
DROP FUNCTION foo(int);
DROP FUNCTION foor(in f2 int, out f1 int, out text);
DROP FUNCTION foob(in f1 int, inout f2 int);
--
-- For my next trick, polymorphic OUT parameters
--
CREATE FUNCTION dup (f1 anyelement, f2 out anyelement, f3 out anyarray)
AS 'select $1, array[$1,$1]' LANGUAGE sql;
SELECT dup(22);
      dup       
----------------
 (22,"{22,22}")
(1 row)

SELECT dup('xyz');	-- fails
ERROR:  could not determine anyarray/anyelement type because input has type "unknown"
SELECT dup('xyz'::text);
        dup        
-------------------
 (xyz,"{xyz,xyz}")
(1 row)

SELECT * FROM dup('xyz'::text);
 f2  |    f3     
-----+-----------
 xyz | {xyz,xyz}
(1 row)

-- equivalent specification
CREATE OR REPLACE FUNCTION dup (inout f2 anyelement, out f3 anyarray)
AS 'select $1, array[$1,$1]' LANGUAGE sql;
SELECT dup(22);
      dup       
----------------
 (22,"{22,22}")
(1 row)

DROP FUNCTION dup(anyelement);
-- fails, no way to deduce outputs
CREATE FUNCTION bad (f1 int, out f2 anyelement, out f3 anyarray)
AS 'select $1, array[$1,$1]' LANGUAGE sql;
ERROR:  cannot determine result data type
DETAIL:  A function returning "anyarray" or "anyelement" must have at least one argument of either type.