5
(5 rows)
+-- recursive view
+CREATE RECURSIVE VIEW nums (n) AS
+ VALUES (1)
+UNION ALL
+ SELECT n+1 FROM nums WHERE n < 5;
+SELECT * FROM nums;
+ n
+---
+ 1
+ 2
+ 3
+ 4
+ 5
+(5 rows)
+
+CREATE OR REPLACE RECURSIVE VIEW nums (n) AS
+ VALUES (1)
+UNION ALL
+ SELECT n+1 FROM nums WHERE n < 6;
+SELECT * FROM nums;
+ n
+---
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+(6 rows)
+
-- This is an infinite loop with UNION ALL, but not with UNION
WITH RECURSIVE t(n) AS (
SELECT 1
parent_department INTEGER REFERENCES department, -- upper department ID
name TEXT -- department name
);
-NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "department_pkey" for table "department"
INSERT INTO department VALUES (0, NULL, 'ROOT');
INSERT INTO department VALUES (1, 0, 'A');
INSERT INTO department VALUES (2, 1, 'B');
-- Check reverse listing
SELECT pg_get_viewdef('vsubdepartment'::regclass);
- pg_get_viewdef
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
- WITH RECURSIVE subdepartment AS (SELECT department.id, department.parent_department, department.name FROM department WHERE (department.name = 'A'::text) UNION ALL SELECT d.id, d.parent_department, d.name FROM department d, subdepartment sd WHERE (d.parent_department = sd.id)) SELECT subdepartment.id, subdepartment.parent_department, subdepartment.name FROM subdepartment;
+ pg_get_viewdef
+-----------------------------------------------
+ WITH RECURSIVE subdepartment AS ( +
+ SELECT department.id, +
+ department.parent_department, +
+ department.name +
+ FROM department +
+ WHERE (department.name = 'A'::text)+
+ UNION ALL +
+ SELECT d.id, +
+ d.parent_department, +
+ d.name +
+ FROM department d, +
+ subdepartment sd +
+ WHERE (d.parent_department = sd.id)+
+ ) +
+ SELECT subdepartment.id, +
+ subdepartment.parent_department, +
+ subdepartment.name +
+ FROM subdepartment;
(1 row)
SELECT pg_get_viewdef('vsubdepartment'::regclass, true);
- pg_get_viewdef
---------------------------------------------------------------------------------------
- WITH RECURSIVE subdepartment AS ( +
- SELECT department.id, department.parent_department, department.name+
- FROM department +
- WHERE department.name = 'A'::text +
- UNION ALL +
- SELECT d.id, d.parent_department, d.name +
- FROM department d, subdepartment sd +
- WHERE d.parent_department = sd.id +
- ) +
- SELECT subdepartment.id, subdepartment.parent_department, subdepartment.name +
+ pg_get_viewdef
+---------------------------------------------
+ WITH RECURSIVE subdepartment AS ( +
+ SELECT department.id, +
+ department.parent_department, +
+ department.name +
+ FROM department +
+ WHERE department.name = 'A'::text+
+ UNION ALL +
+ SELECT d.id, +
+ d.parent_department, +
+ d.name +
+ FROM department d, +
+ subdepartment sd +
+ WHERE d.parent_department = sd.id+
+ ) +
+ SELECT subdepartment.id, +
+ subdepartment.parent_department, +
+ subdepartment.name +
FROM subdepartment;
(1 row)
+-- Another reverse-listing example
+CREATE VIEW sums_1_100 AS
+WITH RECURSIVE t(n) AS (
+ VALUES (1)
+UNION ALL
+ SELECT n+1 FROM t WHERE n < 100
+)
+SELECT sum(n) FROM t;
+\d+ sums_1_100
+ View "public.sums_1_100"
+ Column | Type | Modifiers | Storage | Description
+--------+--------+-----------+---------+-------------
+ sum | bigint | | plain |
+View definition:
+ WITH RECURSIVE t(n) AS (
+ VALUES (1)
+ UNION ALL
+ SELECT t_1.n + 1
+ FROM t t_1
+ WHERE t_1.n < 100
+ )
+ SELECT sum(t.n) AS sum
+ FROM t;
+
-- corner case in which sub-WITH gets initialized first
with recursive q as (
select * from department
id INTEGER PRIMARY KEY,
parent_id INTEGER REFERENCES tree(id)
);
-NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "tree_pkey" for table "tree"
INSERT INTO tree
VALUES (1, NULL), (2, 1), (3,1), (4,2), (5,2), (6,2), (7,3), (8,3),
(9,4), (10,4), (11,7), (12,7), (13,7), (14, 9), (15,11), (16,11);
-- aggregate functions
WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT count(*) FROM x)
SELECT * FROM x;
-ERROR: aggregate functions not allowed in a recursive query's recursive term
+ERROR: aggregate functions are not allowed in a recursive query's recursive term
LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT count(*) F...
^
WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT sum(n) FROM x)
SELECT * FROM x;
-ERROR: aggregate functions not allowed in a recursive query's recursive term
+ERROR: aggregate functions are not allowed in a recursive query's recursive term
LINE 1: WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT sum(n) FRO...
^
-- ORDER BY
10
(55 rows)
+--
+-- test WITH attached to intermediate-level set operation
+--
+WITH outermost(x) AS (
+ SELECT 1
+ UNION (WITH innermost as (SELECT 2)
+ SELECT * FROM innermost
+ UNION SELECT 3)
+)
+SELECT * FROM outermost;
+ x
+---
+ 1
+ 2
+ 3
+(3 rows)
+
+WITH outermost(x) AS (
+ SELECT 1
+ UNION (WITH innermost as (SELECT 2)
+ SELECT * FROM outermost -- fail
+ UNION SELECT * FROM innermost)
+)
+SELECT * FROM outermost;
+ERROR: relation "outermost" does not exist
+LINE 4: SELECT * FROM outermost
+ ^
+DETAIL: There is a WITH item named "outermost", but it cannot be referenced from this part of the query.
+HINT: Use WITH RECURSIVE, or re-order the WITH items to remove forward references.
+WITH RECURSIVE outermost(x) AS (
+ SELECT 1
+ UNION (WITH innermost as (SELECT 2)
+ SELECT * FROM outermost
+ UNION SELECT * FROM innermost)
+)
+SELECT * FROM outermost;
+ x
+---
+ 1
+ 2
+(2 rows)
+
+WITH RECURSIVE outermost(x) AS (
+ WITH innermost as (SELECT 2 FROM outermost) -- fail
+ SELECT * FROM innermost
+ UNION SELECT * from outermost
+)
+SELECT * FROM outermost;
+ERROR: recursive reference to query "outermost" must not appear within a subquery
+LINE 2: WITH innermost as (SELECT 2 FROM outermost)
+ ^
+--
+-- This test will fail with the old implementation of PARAM_EXEC parameter
+-- assignment, because the "q1" Var passed down to A's targetlist subselect
+-- looks exactly like the "A.id" Var passed down to C's subselect, causing
+-- the old code to give them the same runtime PARAM_EXEC slot. But the
+-- lifespans of the two parameters overlap, thanks to B also reading A.
+--
+with
+A as ( select q2 as id, (select q1) as x from int8_tbl ),
+B as ( select id, row_number() over (partition by id) as r from A ),
+C as ( select A.id, array(select B.id from B where B.id = A.id) from A )
+select * from C;
+ id | array
+-------------------+-------------------------------------
+ 456 | {456}
+ 4567890123456789 | {4567890123456789,4567890123456789}
+ 123 | {123}
+ 4567890123456789 | {4567890123456789,4567890123456789}
+ -4567890123456789 | {-4567890123456789}
+(5 rows)
+
+--
+-- Test CTEs read in non-initialization orders
+--
+WITH RECURSIVE
+ tab(id_key,link) AS (VALUES (1,17), (2,17), (3,17), (4,17), (6,17), (5,17)),
+ iter (id_key, row_type, link) AS (
+ SELECT 0, 'base', 17
+ UNION ALL (
+ WITH remaining(id_key, row_type, link, min) AS (
+ SELECT tab.id_key, 'true'::text, iter.link, MIN(tab.id_key) OVER ()
+ FROM tab INNER JOIN iter USING (link)
+ WHERE tab.id_key > iter.id_key
+ ),
+ first_remaining AS (
+ SELECT id_key, row_type, link
+ FROM remaining
+ WHERE id_key=min
+ ),
+ effect AS (
+ SELECT tab.id_key, 'new'::text, tab.link
+ FROM first_remaining e INNER JOIN tab ON e.id_key=tab.id_key
+ WHERE e.row_type = 'false'
+ )
+ SELECT * FROM first_remaining
+ UNION ALL SELECT * FROM effect
+ )
+ )
+SELECT * FROM iter;
+ id_key | row_type | link
+--------+----------+------
+ 0 | base | 17
+ 1 | true | 17
+ 2 | true | 17
+ 3 | true | 17
+ 4 | true | 17
+ 5 | true | 17
+ 6 | true | 17
+(7 rows)
+
+WITH RECURSIVE
+ tab(id_key,link) AS (VALUES (1,17), (2,17), (3,17), (4,17), (6,17), (5,17)),
+ iter (id_key, row_type, link) AS (
+ SELECT 0, 'base', 17
+ UNION (
+ WITH remaining(id_key, row_type, link, min) AS (
+ SELECT tab.id_key, 'true'::text, iter.link, MIN(tab.id_key) OVER ()
+ FROM tab INNER JOIN iter USING (link)
+ WHERE tab.id_key > iter.id_key
+ ),
+ first_remaining AS (
+ SELECT id_key, row_type, link
+ FROM remaining
+ WHERE id_key=min
+ ),
+ effect AS (
+ SELECT tab.id_key, 'new'::text, tab.link
+ FROM first_remaining e INNER JOIN tab ON e.id_key=tab.id_key
+ WHERE e.row_type = 'false'
+ )
+ SELECT * FROM first_remaining
+ UNION ALL SELECT * FROM effect
+ )
+ )
+SELECT * FROM iter;
+ id_key | row_type | link
+--------+----------+------
+ 0 | base | 17
+ 1 | true | 17
+ 2 | true | 17
+ 3 | true | 17
+ 4 | true | 17
+ 5 | true | 17
+ 6 | true | 17
+(7 rows)
+
--
-- Data-modifying statements in WITH
--
-400
(22 rows)
+-- data-modifying WITH containing INSERT...ON CONFLICT DO UPDATE
+CREATE TABLE z AS SELECT i AS k, (i || ' v')::text v FROM generate_series(1, 16, 3) i;
+ALTER TABLE z ADD UNIQUE (k);
+WITH t AS (
+ INSERT INTO z SELECT i, 'insert'
+ FROM generate_series(0, 16) i
+ ON CONFLICT (k) DO UPDATE SET v = z.v || ', now update'
+ RETURNING *
+)
+SELECT * FROM t JOIN y ON t.k = y.a ORDER BY a, k;
+ k | v | a
+---+--------+---
+ 0 | insert | 0
+ 0 | insert | 0
+(2 rows)
+
+-- Test EXCLUDED.* reference within CTE
+WITH aa AS (
+ INSERT INTO z VALUES(1, 5) ON CONFLICT (k) DO UPDATE SET v = EXCLUDED.v
+ WHERE z.k != EXCLUDED.k
+ RETURNING *
+)
+SELECT * FROM aa;
+ k | v
+---+---
+(0 rows)
+
+-- New query/snapshot demonstrates side-effects of previous query.
+SELECT * FROM z ORDER BY k;
+ k | v
+----+------------------
+ 0 | insert
+ 1 | 1 v, now update
+ 2 | insert
+ 3 | insert
+ 4 | 4 v, now update
+ 5 | insert
+ 6 | insert
+ 7 | 7 v, now update
+ 8 | insert
+ 9 | insert
+ 10 | 10 v, now update
+ 11 | insert
+ 12 | insert
+ 13 | 13 v, now update
+ 14 | insert
+ 15 | insert
+ 16 | 16 v, now update
+(17 rows)
+
+--
+-- Ensure subqueries within the update clause work, even if they
+-- reference outside values
+--
+WITH aa AS (SELECT 1 a, 2 b)
+INSERT INTO z VALUES(1, 'insert')
+ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 1 LIMIT 1);
+WITH aa AS (SELECT 1 a, 2 b)
+INSERT INTO z VALUES(1, 'insert')
+ON CONFLICT (k) DO UPDATE SET v = ' update' WHERE z.k = (SELECT a FROM aa);
+WITH aa AS (SELECT 1 a, 2 b)
+INSERT INTO z VALUES(1, 'insert')
+ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 1 LIMIT 1);
+WITH aa AS (SELECT 'a' a, 'b' b UNION ALL SELECT 'a' a, 'b' b)
+INSERT INTO z VALUES(1, 'insert')
+ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 'a' LIMIT 1);
+WITH aa AS (SELECT 1 a, 2 b)
+INSERT INTO z VALUES(1, (SELECT b || ' insert' FROM aa WHERE a = 1 ))
+ON CONFLICT (k) DO UPDATE SET v = (SELECT b || ' update' FROM aa WHERE a = 1 LIMIT 1);
+-- This shows an attempt to update an invisible row, which should really be
+-- reported as a cardinality violation, but it doesn't seem worth fixing:
+WITH simpletup AS (
+ SELECT 2 k, 'Green' v),
+upsert_cte AS (
+ INSERT INTO z VALUES(2, 'Blue') ON CONFLICT (k) DO
+ UPDATE SET (k, v) = (SELECT k, v FROM simpletup WHERE simpletup.k = z.k)
+ RETURNING k, v)
+INSERT INTO z VALUES(2, 'Red') ON CONFLICT (k) DO
+UPDATE SET (k, v) = (SELECT k, v FROM upsert_cte WHERE upsert_cte.k = z.k)
+RETURNING k, v;
+ERROR: attempted to update invisible tuple
+DROP TABLE z;
-- check that run to completion happens in proper ordering
TRUNCATE TABLE y;
INSERT INTO y SELECT generate_series(1, 3);
DROP TRIGGER y_trig ON y;
DROP FUNCTION y_trigger();
+-- WITH attached to inherited UPDATE or DELETE
+CREATE TEMP TABLE parent ( id int, val text );
+CREATE TEMP TABLE child1 ( ) INHERITS ( parent );
+CREATE TEMP TABLE child2 ( ) INHERITS ( parent );
+INSERT INTO parent VALUES ( 1, 'p1' );
+INSERT INTO child1 VALUES ( 11, 'c11' ),( 12, 'c12' );
+INSERT INTO child2 VALUES ( 23, 'c21' ),( 24, 'c22' );
+WITH rcte AS ( SELECT sum(id) AS totalid FROM parent )
+UPDATE parent SET id = id + totalid FROM rcte;
+SELECT * FROM parent;
+ id | val
+----+-----
+ 72 | p1
+ 82 | c11
+ 83 | c12
+ 94 | c21
+ 95 | c22
+(5 rows)
+
+WITH wcte AS ( INSERT INTO child1 VALUES ( 42, 'new' ) RETURNING id AS newid )
+UPDATE parent SET id = id + newid FROM wcte;
+SELECT * FROM parent;
+ id | val
+-----+-----
+ 114 | p1
+ 42 | new
+ 124 | c11
+ 125 | c12
+ 136 | c21
+ 137 | c22
+(6 rows)
+
+WITH rcte AS ( SELECT max(id) AS maxid FROM parent )
+DELETE FROM parent USING rcte WHERE id = maxid;
+SELECT * FROM parent;
+ id | val
+-----+-----
+ 114 | p1
+ 42 | new
+ 124 | c11
+ 125 | c12
+ 136 | c21
+(5 rows)
+
+WITH wcte AS ( INSERT INTO child2 VALUES ( 42, 'new2' ) RETURNING id AS newid )
+DELETE FROM parent USING wcte WHERE id = newid;
+SELECT * FROM parent;
+ id | val
+-----+------
+ 114 | p1
+ 124 | c11
+ 125 | c12
+ 136 | c21
+ 42 | new2
+(5 rows)
+
+-- check EXPLAIN VERBOSE for a wCTE with RETURNING
+EXPLAIN (VERBOSE, COSTS OFF)
+WITH wcte AS ( INSERT INTO int8_tbl VALUES ( 42, 47 ) RETURNING q2 )
+DELETE FROM a USING wcte WHERE aa = q2;
+ QUERY PLAN
+----------------------------------------------------
+ Delete on public.a
+ Delete on public.a
+ Delete on public.b
+ Delete on public.c
+ Delete on public.d
+ CTE wcte
+ -> Insert on public.int8_tbl
+ Output: int8_tbl.q2
+ -> Result
+ Output: '42'::bigint, '47'::bigint
+ -> Nested Loop
+ Output: a.ctid, wcte.*
+ Join Filter: (a.aa = wcte.q2)
+ -> Seq Scan on public.a
+ Output: a.ctid, a.aa
+ -> CTE Scan on wcte
+ Output: wcte.*, wcte.q2
+ -> Nested Loop
+ Output: b.ctid, wcte.*
+ Join Filter: (b.aa = wcte.q2)
+ -> Seq Scan on public.b
+ Output: b.ctid, b.aa
+ -> CTE Scan on wcte
+ Output: wcte.*, wcte.q2
+ -> Nested Loop
+ Output: c.ctid, wcte.*
+ Join Filter: (c.aa = wcte.q2)
+ -> Seq Scan on public.c
+ Output: c.ctid, c.aa
+ -> CTE Scan on wcte
+ Output: wcte.*, wcte.q2
+ -> Nested Loop
+ Output: d.ctid, wcte.*
+ Join Filter: (d.aa = wcte.q2)
+ -> Seq Scan on public.d
+ Output: d.ctid, d.aa
+ -> CTE Scan on wcte
+ Output: wcte.*, wcte.q2
+(38 rows)
+
-- error cases
-- data-modifying WITH tries to use its own output
WITH RECURSIVE t AS (
VALUES(FALSE);
ERROR: conditional DO INSTEAD rules are not supported for data-modifying statements in WITH
DROP RULE y_rule ON y;
+-- check that parser lookahead for WITH doesn't cause any odd behavior
+create table foo (with baz); -- fail, WITH is a reserved word
+ERROR: syntax error at or near "with"
+LINE 1: create table foo (with baz);
+ ^
+create table foo (with ordinality); -- fail, WITH is a reserved word
+ERROR: syntax error at or near "with"
+LINE 1: create table foo (with ordinality);
+ ^
+with ordinality as (select 1 as x) select * from ordinality;
+ x
+---
+ 1
+(1 row)
+
projects / postgresql / blobdiff