-- -- Tests for common table expressions (WITH query, ... SELECT ...) -- -- Basic WITH WITH q1(x,y) AS (SELECT 1,2) SELECT * FROM q1, q1 AS q2; -- Multiple uses are evaluated only once SELECT count(*) FROM ( WITH q1(x) AS (SELECT random() FROM generate_series(1, 5)) SELECT * FROM q1 UNION SELECT * FROM q1 ) ss; -- WITH RECURSIVE -- sum of 1..100 WITH RECURSIVE t(n) AS ( VALUES (1) UNION ALL SELECT n+1 FROM t WHERE n < 100 ) SELECT sum(n) FROM t; WITH RECURSIVE t(n) AS ( SELECT (VALUES(1)) UNION ALL SELECT n+1 FROM t WHERE n < 5 ) SELECT * FROM t; -- UNION DISTINCT requires hashable type WITH RECURSIVE t(n) AS ( VALUES (1::money) UNION SELECT n+1::money FROM t WHERE n < 100::money ) SELECT sum(n) FROM t; -- recursive view CREATE RECURSIVE VIEW nums (n) AS VALUES (1) UNION ALL SELECT n+1 FROM nums WHERE n < 5; SELECT * FROM nums; CREATE OR REPLACE RECURSIVE VIEW nums (n) AS VALUES (1) UNION ALL SELECT n+1 FROM nums WHERE n < 6; SELECT * FROM nums; -- This is an infinite loop with UNION ALL, but not with UNION WITH RECURSIVE t(n) AS ( SELECT 1 UNION SELECT 10-n FROM t) SELECT * FROM t; -- This'd be an infinite loop, but outside query reads only as much as needed WITH RECURSIVE t(n) AS ( VALUES (1) UNION ALL SELECT n+1 FROM t) SELECT * FROM t LIMIT 10; -- UNION case should have same property WITH RECURSIVE t(n) AS ( SELECT 1 UNION SELECT n+1 FROM t) SELECT * FROM t LIMIT 10; -- Test behavior with an unknown-type literal in the WITH WITH q AS (SELECT 'foo' AS x) SELECT x, pg_typeof(x) FROM q; WITH RECURSIVE t(n) AS ( SELECT 'foo' UNION ALL SELECT n || ' bar' FROM t WHERE length(n) < 20 ) SELECT n, pg_typeof(n) FROM t; -- In a perfect world, this would work and resolve the literal as int ... -- but for now, we have to be content with resolving to text too soon. WITH RECURSIVE t(n) AS ( SELECT '7' UNION ALL SELECT n+1 FROM t WHERE n < 10 ) SELECT n, pg_typeof(n) FROM t; -- Deeply nested WITH caused a list-munging problem in v13 -- Detection of cross-references and self-references WITH RECURSIVE w1(c1) AS (WITH w2(c2) AS (WITH w3(c3) AS (WITH w4(c4) AS (WITH w5(c5) AS (WITH RECURSIVE w6(c6) AS (WITH w6(c6) AS (WITH w8(c8) AS (SELECT 1) SELECT * FROM w8) SELECT * FROM w6) SELECT * FROM w6) SELECT * FROM w5) SELECT * FROM w4) SELECT * FROM w3) SELECT * FROM w2) SELECT * FROM w1; -- Detection of invalid self-references WITH RECURSIVE outermost(x) AS ( SELECT 1 UNION (WITH innermost1 AS ( SELECT 2 UNION (WITH innermost2 AS ( SELECT 3 UNION (WITH innermost3 AS ( SELECT 4 UNION (WITH innermost4 AS ( SELECT 5 UNION (WITH innermost5 AS ( SELECT 6 UNION (WITH innermost6 AS (SELECT 7) SELECT * FROM innermost6)) SELECT * FROM innermost5)) SELECT * FROM innermost4)) SELECT * FROM innermost3)) SELECT * FROM innermost2)) SELECT * FROM outermost UNION SELECT * FROM innermost1) ) SELECT * FROM outermost ORDER BY 1; -- -- Some examples with a tree -- -- department structure represented here is as follows: -- -- ROOT-+->A-+->B-+->C -- | | -- | +->D-+->F -- +->E-+->G CREATE TEMP TABLE department ( id INTEGER PRIMARY KEY, -- department ID parent_department INTEGER REFERENCES department, -- upper department ID name TEXT -- department name ); INSERT INTO department VALUES (0, NULL, 'ROOT'); INSERT INTO department VALUES (1, 0, 'A'); INSERT INTO department VALUES (2, 1, 'B'); INSERT INTO department VALUES (3, 2, 'C'); INSERT INTO department VALUES (4, 2, 'D'); INSERT INTO department VALUES (5, 0, 'E'); INSERT INTO department VALUES (6, 4, 'F'); INSERT INTO department VALUES (7, 5, 'G'); -- extract all departments under 'A'. Result should be A, B, C, D and F WITH RECURSIVE subdepartment AS ( -- non recursive term SELECT name as root_name, * FROM department WHERE name = 'A' UNION ALL -- recursive term SELECT sd.root_name, d.* FROM department AS d, subdepartment AS sd WHERE d.parent_department = sd.id ) SELECT * FROM subdepartment ORDER BY name; -- extract all departments under 'A' with "level" number WITH RECURSIVE subdepartment(level, id, parent_department, name) AS ( -- non recursive term SELECT 1, * FROM department WHERE name = 'A' UNION ALL -- recursive term SELECT sd.level + 1, d.* FROM department AS d, subdepartment AS sd WHERE d.parent_department = sd.id ) SELECT * FROM subdepartment ORDER BY name; -- extract all departments under 'A' with "level" number. -- Only shows level 2 or more WITH RECURSIVE subdepartment(level, id, parent_department, name) AS ( -- non recursive term SELECT 1, * FROM department WHERE name = 'A' UNION ALL -- recursive term SELECT sd.level + 1, d.* FROM department AS d, subdepartment AS sd WHERE d.parent_department = sd.id ) SELECT * FROM subdepartment WHERE level >= 2 ORDER BY name; -- "RECURSIVE" is ignored if the query has no self-reference WITH RECURSIVE subdepartment AS ( -- note lack of recursive UNION structure SELECT * FROM department WHERE name = 'A' ) SELECT * FROM subdepartment ORDER BY name; -- inside subqueries SELECT count(*) FROM ( WITH RECURSIVE t(n) AS ( SELECT 1 UNION ALL SELECT n + 1 FROM t WHERE n < 500 ) SELECT * FROM t) AS t WHERE n < ( SELECT count(*) FROM ( WITH RECURSIVE t(n) AS ( SELECT 1 UNION ALL SELECT n + 1 FROM t WHERE n < 100 ) SELECT * FROM t WHERE n < 50000 ) AS t WHERE n < 100); -- use same CTE twice at different subquery levels WITH q1(x,y) AS ( SELECT hundred, sum(ten) FROM tenk1 GROUP BY hundred ) SELECT count(*) FROM q1 WHERE y > (SELECT sum(y)/100 FROM q1 qsub); -- via a VIEW CREATE TEMPORARY VIEW vsubdepartment AS WITH RECURSIVE subdepartment AS ( -- non recursive term SELECT * FROM department WHERE name = 'A' UNION ALL -- recursive term SELECT d.* FROM department AS d, subdepartment AS sd WHERE d.parent_department = sd.id ) SELECT * FROM subdepartment; SELECT * FROM vsubdepartment ORDER BY name; -- Check reverse listing SELECT pg_get_viewdef('vsubdepartment'::regclass); SELECT pg_get_viewdef('vsubdepartment'::regclass, true); -- 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 -- corner case in which sub-WITH gets initialized first with recursive q as ( select * from department union all (with x as (select * from q) select * from x) ) select * from q limit 24; with recursive q as ( select * from department union all (with recursive x as ( select * from department union all (select * from q union all select * from x) ) select * from x) ) select * from q limit 32; -- recursive term has sub-UNION WITH RECURSIVE t(i,j) AS ( VALUES (1,2) UNION ALL SELECT t2.i, t.j+1 FROM (SELECT 2 AS i UNION ALL SELECT 3 AS i) AS t2 JOIN t ON (t2.i = t.i+1)) SELECT * FROM t; -- -- different tree example -- CREATE TEMPORARY TABLE tree( id INTEGER PRIMARY KEY, parent_id INTEGER REFERENCES tree(id) ); 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); -- -- get all paths from "second level" nodes to leaf nodes -- WITH RECURSIVE t(id, path) AS ( VALUES(1,ARRAY[]::integer[]) UNION ALL SELECT tree.id, t.path || tree.id FROM tree JOIN t ON (tree.parent_id = t.id) ) SELECT t1.*, t2.* FROM t AS t1 JOIN t AS t2 ON (t1.path[1] = t2.path[1] AND array_upper(t1.path,1) = 1 AND array_upper(t2.path,1) > 1) ORDER BY t1.id, t2.id; -- just count 'em WITH RECURSIVE t(id, path) AS ( VALUES(1,ARRAY[]::integer[]) UNION ALL SELECT tree.id, t.path || tree.id FROM tree JOIN t ON (tree.parent_id = t.id) ) SELECT t1.id, count(t2.*) FROM t AS t1 JOIN t AS t2 ON (t1.path[1] = t2.path[1] AND array_upper(t1.path,1) = 1 AND array_upper(t2.path,1) > 1) GROUP BY t1.id ORDER BY t1.id; -- this variant tickled a whole-row-variable bug in 8.4devel WITH RECURSIVE t(id, path) AS ( VALUES(1,ARRAY[]::integer[]) UNION ALL SELECT tree.id, t.path || tree.id FROM tree JOIN t ON (tree.parent_id = t.id) ) SELECT t1.id, t2.path, t2 FROM t AS t1 JOIN t AS t2 ON (t1.id=t2.id); -- SEARCH clause create temp table graph0( f int, t int, label text ); insert into graph0 values (1, 2, 'arc 1 -> 2'), (1, 3, 'arc 1 -> 3'), (2, 3, 'arc 2 -> 3'), (1, 4, 'arc 1 -> 4'), (4, 5, 'arc 4 -> 5'); explain (verbose, costs off) with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t set seq select * from search_graph order by seq; with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t set seq select * from search_graph order by seq; with recursive search_graph(f, t, label) as ( select * from graph0 g union distinct select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t set seq select * from search_graph order by seq; explain (verbose, costs off) with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search breadth first by f, t set seq select * from search_graph order by seq; with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search breadth first by f, t set seq select * from search_graph order by seq; with recursive search_graph(f, t, label) as ( select * from graph0 g union distinct select g.* from graph0 g, search_graph sg where g.f = sg.t ) search breadth first by f, t set seq select * from search_graph order by seq; -- a constant initial value causes issues for EXPLAIN explain (verbose, costs off) with recursive test as ( select 1 as x union all select x + 1 from test ) search depth first by x set y select * from test limit 5; with recursive test as ( select 1 as x union all select x + 1 from test ) search depth first by x set y select * from test limit 5; explain (verbose, costs off) with recursive test as ( select 1 as x union all select x + 1 from test ) search breadth first by x set y select * from test limit 5; with recursive test as ( select 1 as x union all select x + 1 from test ) search breadth first by x set y select * from test limit 5; -- various syntax errors with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by foo, tar set seq select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t set label select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t, f set seq select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph0 g union all select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t set seq select * from search_graph order by seq; with recursive search_graph(f, t, label) as ( select * from graph0 g union all (select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t) ) search depth first by f, t set seq select * from search_graph order by seq; -- check that we distinguish same CTE name used at different levels -- (this case could be supported, perhaps, but it isn't today) with recursive x(col) as ( select 1 union (with x as (select * from x) select * from x) ) search depth first by col set seq select * from x; -- test ruleutils and view expansion create temp view v_search as with recursive search_graph(f, t, label) as ( select * from graph0 g union all select g.* from graph0 g, search_graph sg where g.f = sg.t ) search depth first by f, t set seq select f, t, label from search_graph; select pg_get_viewdef('v_search'); select * from v_search; -- -- test cycle detection -- create temp table graph( f int, t int, label text ); insert into graph values (1, 2, 'arc 1 -> 2'), (1, 3, 'arc 1 -> 3'), (2, 3, 'arc 2 -> 3'), (1, 4, 'arc 1 -> 4'), (4, 5, 'arc 4 -> 5'), (5, 1, 'arc 5 -> 1'); with recursive search_graph(f, t, label, is_cycle, path) as ( select *, false, array[row(g.f, g.t)] from graph g union all select g.*, row(g.f, g.t) = any(path), path || row(g.f, g.t) from graph g, search_graph sg where g.f = sg.t and not is_cycle ) select * from search_graph; -- UNION DISTINCT exercises row type hashing support with recursive search_graph(f, t, label, is_cycle, path) as ( select *, false, array[row(g.f, g.t)] from graph g union distinct select g.*, row(g.f, g.t) = any(path), path || row(g.f, g.t) from graph g, search_graph sg where g.f = sg.t and not is_cycle ) select * from search_graph; -- ordering by the path column has same effect as SEARCH DEPTH FIRST with recursive search_graph(f, t, label, is_cycle, path) as ( select *, false, array[row(g.f, g.t)] from graph g union all select g.*, row(g.f, g.t) = any(path), path || row(g.f, g.t) from graph g, search_graph sg where g.f = sg.t and not is_cycle ) select * from search_graph order by path; -- CYCLE clause explain (verbose, costs off) with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union distinct select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle to 'Y' default 'N' using path select * from search_graph; explain (verbose, costs off) with recursive test as ( select 0 as x union all select (x + 1) % 10 from test ) cycle x set is_cycle using path select * from test; with recursive test as ( select 0 as x union all select (x + 1) % 10 from test ) cycle x set is_cycle using path select * from test; with recursive test as ( select 0 as x union all select (x + 1) % 10 from test where not is_cycle -- redundant, but legal ) cycle x set is_cycle using path select * from test; -- multiple CTEs with recursive graph(f, t, label) as ( values (1, 2, 'arc 1 -> 2'), (1, 3, 'arc 1 -> 3'), (2, 3, 'arc 2 -> 3'), (1, 4, 'arc 1 -> 4'), (4, 5, 'arc 4 -> 5'), (5, 1, 'arc 5 -> 1') ), search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle to true default false using path select f, t, label from search_graph; -- star expansion with recursive a as ( select 1 as b union all select * from a ) cycle b set c using p select * from a; -- search+cycle with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) search depth first by f, t set seq cycle f, t set is_cycle using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) search breadth first by f, t set seq cycle f, t set is_cycle using path select * from search_graph; -- various syntax errors with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle foo, tar set is_cycle using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle to true default 55 using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle to point '(1,1)' default point '(0,0)' using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set label to true default false using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle to true default false using label select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set foo to true default false using foo select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t, f set is_cycle to true default false using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) search depth first by f, t set foo cycle f, t set foo to true default false using path select * from search_graph; with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) search depth first by f, t set foo cycle f, t set is_cycle to true default false using foo select * from search_graph; -- test ruleutils and view expansion create temp view v_cycle1 as with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle using path select f, t, label from search_graph; create temp view v_cycle2 as with recursive search_graph(f, t, label) as ( select * from graph g union all select g.* from graph g, search_graph sg where g.f = sg.t ) cycle f, t set is_cycle to 'Y' default 'N' using path select f, t, label from search_graph; select pg_get_viewdef('v_cycle1'); select pg_get_viewdef('v_cycle2'); select * from v_cycle1; select * from v_cycle2; -- -- test multiple WITH queries -- WITH RECURSIVE y (id) AS (VALUES (1)), x (id) AS (SELECT * FROM y UNION ALL SELECT id+1 FROM x WHERE id < 5) SELECT * FROM x; -- forward reference OK WITH RECURSIVE x(id) AS (SELECT * FROM y UNION ALL SELECT id+1 FROM x WHERE id < 5), y(id) AS (values (1)) SELECT * FROM x; WITH RECURSIVE x(id) AS (VALUES (1) UNION ALL SELECT id+1 FROM x WHERE id < 5), y(id) AS (VALUES (1) UNION ALL SELECT id+1 FROM y WHERE id < 10) SELECT y.*, x.* FROM y LEFT JOIN x USING (id); WITH RECURSIVE x(id) AS (VALUES (1) UNION ALL SELECT id+1 FROM x WHERE id < 5), y(id) AS (VALUES (1) UNION ALL SELECT id+1 FROM x WHERE id < 10) SELECT y.*, x.* FROM y LEFT JOIN x USING (id); WITH RECURSIVE x(id) AS (SELECT 1 UNION ALL SELECT id+1 FROM x WHERE id < 3 ), y(id) AS (SELECT * FROM x UNION ALL SELECT * FROM x), z(id) AS (SELECT * FROM x UNION ALL SELECT id+1 FROM z WHERE id < 10) SELECT * FROM z; WITH RECURSIVE x(id) AS (SELECT 1 UNION ALL SELECT id+1 FROM x WHERE id < 3 ), y(id) AS (SELECT * FROM x UNION ALL SELECT * FROM x), z(id) AS (SELECT * FROM y UNION ALL SELECT id+1 FROM z WHERE id < 10) SELECT * FROM z; -- -- Test WITH attached to a data-modifying statement -- CREATE TEMPORARY TABLE y (a INTEGER); INSERT INTO y SELECT generate_series(1, 10); WITH t AS ( SELECT a FROM y ) INSERT INTO y SELECT a+20 FROM t RETURNING *; SELECT * FROM y; WITH t AS ( SELECT a FROM y ) UPDATE y SET a = y.a-10 FROM t WHERE y.a > 20 AND t.a = y.a RETURNING y.a; SELECT * FROM y; WITH RECURSIVE t(a) AS ( SELECT 11 UNION ALL SELECT a+1 FROM t WHERE a < 50 ) DELETE FROM y USING t WHERE t.a = y.a RETURNING y.a; SELECT * FROM y; DROP TABLE y; -- -- error cases -- WITH x(n, b) AS (SELECT 1) SELECT * FROM x; -- INTERSECT WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT SELECT n+1 FROM x) SELECT * FROM x; WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT ALL SELECT n+1 FROM x) SELECT * FROM x; -- EXCEPT WITH RECURSIVE x(n) AS (SELECT 1 EXCEPT SELECT n+1 FROM x) SELECT * FROM x; WITH RECURSIVE x(n) AS (SELECT 1 EXCEPT ALL SELECT n+1 FROM x) SELECT * FROM x; -- no non-recursive term WITH RECURSIVE x(n) AS (SELECT n FROM x) SELECT * FROM x; -- recursive term in the left hand side (strictly speaking, should allow this) WITH RECURSIVE x(n) AS (SELECT n FROM x UNION ALL SELECT 1) SELECT * FROM x; CREATE TEMPORARY TABLE y (a INTEGER); INSERT INTO y SELECT generate_series(1, 10); -- LEFT JOIN WITH RECURSIVE x(n) AS (SELECT a FROM y WHERE a = 1 UNION ALL SELECT x.n+1 FROM y LEFT JOIN x ON x.n = y.a WHERE n < 10) SELECT * FROM x; -- RIGHT JOIN WITH RECURSIVE x(n) AS (SELECT a FROM y WHERE a = 1 UNION ALL SELECT x.n+1 FROM x RIGHT JOIN y ON x.n = y.a WHERE n < 10) SELECT * FROM x; -- FULL JOIN WITH RECURSIVE x(n) AS (SELECT a FROM y WHERE a = 1 UNION ALL SELECT x.n+1 FROM x FULL JOIN y ON x.n = y.a WHERE n < 10) SELECT * FROM x; -- subquery WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x WHERE n IN (SELECT * FROM x)) SELECT * FROM x; -- aggregate functions WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT count(*) FROM x) SELECT * FROM x; WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT sum(n) FROM x) SELECT * FROM x; -- ORDER BY WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x ORDER BY 1) SELECT * FROM x; -- LIMIT/OFFSET WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x LIMIT 10 OFFSET 1) SELECT * FROM x; -- FOR UPDATE WITH RECURSIVE x(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM x FOR UPDATE) SELECT * FROM x; -- target list has a recursive query name WITH RECURSIVE x(id) AS (values (1) UNION ALL SELECT (SELECT * FROM x) FROM x WHERE id < 5 ) SELECT * FROM x; -- mutual recursive query (not implemented) WITH RECURSIVE x (id) AS (SELECT 1 UNION ALL SELECT id+1 FROM y WHERE id < 5), y (id) AS (SELECT 1 UNION ALL SELECT id+1 FROM x WHERE id < 5) SELECT * FROM x; -- non-linear recursion is not allowed WITH RECURSIVE foo(i) AS (values (1) UNION ALL (SELECT i+1 FROM foo WHERE i < 10 UNION ALL SELECT i+1 FROM foo WHERE i < 5) ) SELECT * FROM foo; WITH RECURSIVE foo(i) AS (values (1) UNION ALL SELECT * FROM (SELECT i+1 FROM foo WHERE i < 10 UNION ALL SELECT i+1 FROM foo WHERE i < 5) AS t ) SELECT * FROM foo; WITH RECURSIVE foo(i) AS (values (1) UNION ALL (SELECT i+1 FROM foo WHERE i < 10 EXCEPT SELECT i+1 FROM foo WHERE i < 5) ) SELECT * FROM foo; WITH RECURSIVE foo(i) AS (values (1) UNION ALL (SELECT i+1 FROM foo WHERE i < 10 INTERSECT SELECT i+1 FROM foo WHERE i < 5) ) SELECT * FROM foo; -- Wrong type induced from non-recursive term WITH RECURSIVE foo(i) AS (SELECT i FROM (VALUES(1),(2)) t(i) UNION ALL SELECT (i+1)::numeric(10,0) FROM foo WHERE i < 10) SELECT * FROM foo; -- rejects different typmod, too (should we allow this?) WITH RECURSIVE foo(i) AS (SELECT i::numeric(3,0) FROM (VALUES(1),(2)) t(i) UNION ALL SELECT (i+1)::numeric(10,0) FROM foo WHERE i < 10) SELECT * FROM foo; -- disallow OLD/NEW reference in CTE CREATE TEMPORARY TABLE x (n integer); CREATE RULE r2 AS ON UPDATE TO x DO INSTEAD WITH t AS (SELECT OLD.*) UPDATE y SET a = t.n FROM t; -- -- test for bug #4902 -- with cte(foo) as ( values(42) ) values((select foo from cte)); with cte(foo) as ( select 42 ) select * from ((select foo from cte)) q; -- test CTE referencing an outer-level variable (to see that changed-parameter -- signaling still works properly after fixing this bug) select ( with cte(foo) as ( values(f1) ) select (select foo from cte) ) from int4_tbl; select ( with cte(foo) as ( values(f1) ) values((select foo from cte)) ) from int4_tbl; -- -- test for nested-recursive-WITH bug -- WITH RECURSIVE t(j) AS ( WITH RECURSIVE s(i) AS ( VALUES (1) UNION ALL SELECT i+1 FROM s WHERE i < 10 ) SELECT i FROM s UNION ALL SELECT j+1 FROM t WHERE j < 10 ) SELECT * FROM t; -- -- 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 ORDER BY 1; WITH outermost(x) AS ( SELECT 1 UNION (WITH innermost as (SELECT 2) SELECT * FROM outermost -- fail UNION SELECT * FROM innermost) ) SELECT * FROM outermost ORDER BY 1; WITH RECURSIVE outermost(x) AS ( SELECT 1 UNION (WITH innermost as (SELECT 2) SELECT * FROM outermost UNION SELECT * FROM innermost) ) SELECT * FROM outermost ORDER BY 1; WITH RECURSIVE outermost(x) AS ( WITH innermost as (SELECT 2 FROM outermost) -- fail SELECT * FROM innermost UNION SELECT * from outermost ) SELECT * FROM outermost ORDER BY 1; -- -- 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; -- -- 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; 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; -- -- Data-modifying statements in WITH -- -- INSERT ... RETURNING WITH t AS ( INSERT INTO y VALUES (11), (12), (13), (14), (15), (16), (17), (18), (19), (20) RETURNING * ) SELECT * FROM t; SELECT * FROM y; -- UPDATE ... RETURNING WITH t AS ( UPDATE y SET a=a+1 RETURNING * ) SELECT * FROM t; SELECT * FROM y; -- DELETE ... RETURNING WITH t AS ( DELETE FROM y WHERE a <= 10 RETURNING * ) SELECT * FROM t; SELECT * FROM y; -- forward reference WITH RECURSIVE t AS ( INSERT INTO y SELECT a+5 FROM t2 WHERE a > 5 RETURNING * ), t2 AS ( UPDATE y SET a=a-11 RETURNING * ) SELECT * FROM t UNION ALL SELECT * FROM t2; SELECT * FROM y; -- unconditional DO INSTEAD rule CREATE RULE y_rule AS ON DELETE TO y DO INSTEAD INSERT INTO y VALUES(42) RETURNING *; WITH t AS ( DELETE FROM y RETURNING * ) SELECT * FROM t; SELECT * FROM y; DROP RULE y_rule ON y; -- check merging of outer CTE with CTE in a rule action CREATE TEMP TABLE bug6051 AS select i from generate_series(1,3) as t(i); SELECT * FROM bug6051; WITH t1 AS ( DELETE FROM bug6051 RETURNING * ) INSERT INTO bug6051 SELECT * FROM t1; SELECT * FROM bug6051; CREATE TEMP TABLE bug6051_2 (i int); CREATE RULE bug6051_ins AS ON INSERT TO bug6051 DO INSTEAD INSERT INTO bug6051_2 VALUES(NEW.i); WITH t1 AS ( DELETE FROM bug6051 RETURNING * ) INSERT INTO bug6051 SELECT * FROM t1; SELECT * FROM bug6051; SELECT * FROM bug6051_2; -- check INSERT ... SELECT rule actions are disallowed on commands -- that have modifyingCTEs CREATE OR REPLACE RULE bug6051_ins AS ON INSERT TO bug6051 DO INSTEAD INSERT INTO bug6051_2 SELECT NEW.i; WITH t1 AS ( DELETE FROM bug6051 RETURNING * ) INSERT INTO bug6051 SELECT * FROM t1; -- silly example to verify that hasModifyingCTE flag is propagated CREATE TEMP TABLE bug6051_3 AS SELECT a FROM generate_series(11,13) AS a; CREATE RULE bug6051_3_ins AS ON INSERT TO bug6051_3 DO INSTEAD SELECT i FROM bug6051_2; BEGIN; SET LOCAL debug_parallel_query = on; WITH t1 AS ( DELETE FROM bug6051_3 RETURNING * ) INSERT INTO bug6051_3 SELECT * FROM t1; COMMIT; SELECT * FROM bug6051_3; -- check case where CTE reference is removed due to optimization EXPLAIN (VERBOSE, COSTS OFF) SELECT q1 FROM ( WITH t_cte AS (SELECT * FROM int8_tbl t) SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub FROM int8_tbl i8 ) ss; SELECT q1 FROM ( WITH t_cte AS (SELECT * FROM int8_tbl t) SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub FROM int8_tbl i8 ) ss; EXPLAIN (VERBOSE, COSTS OFF) SELECT q1 FROM ( WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub FROM int8_tbl i8 ) ss; SELECT q1 FROM ( WITH t_cte AS MATERIALIZED (SELECT * FROM int8_tbl t) SELECT q1, (SELECT q2 FROM t_cte WHERE t_cte.q1 = i8.q1) AS t_sub FROM int8_tbl i8 ) ss; -- a truly recursive CTE in the same list WITH RECURSIVE t(a) AS ( SELECT 0 UNION ALL SELECT a+1 FROM t WHERE a+1 < 5 ), t2 as ( INSERT INTO y SELECT * FROM t RETURNING * ) SELECT * FROM t2 JOIN y USING (a) ORDER BY a; SELECT * FROM y; -- data-modifying WITH in a modifying statement WITH t AS ( DELETE FROM y WHERE a <= 10 RETURNING * ) INSERT INTO y SELECT -a FROM t RETURNING *; SELECT * FROM y; -- check that WITH query is run to completion even if outer query isn't WITH t AS ( UPDATE y SET a = a * 100 RETURNING * ) SELECT * FROM t LIMIT 10; SELECT * FROM y; -- data-modifying WITH containing INSERT...ON CONFLICT DO UPDATE CREATE TABLE withz AS SELECT i AS k, (i || ' v')::text v FROM generate_series(1, 16, 3) i; ALTER TABLE withz ADD UNIQUE (k); WITH t AS ( INSERT INTO withz SELECT i, 'insert' FROM generate_series(0, 16) i ON CONFLICT (k) DO UPDATE SET v = withz.v || ', now update' RETURNING * ) SELECT * FROM t JOIN y ON t.k = y.a ORDER BY a, k; -- Test EXCLUDED.* reference within CTE WITH aa AS ( INSERT INTO withz VALUES(1, 5) ON CONFLICT (k) DO UPDATE SET v = EXCLUDED.v WHERE withz.k != EXCLUDED.k RETURNING * ) SELECT * FROM aa; -- New query/snapshot demonstrates side-effects of previous query. SELECT * FROM withz ORDER BY k; -- -- Ensure subqueries within the update clause work, even if they -- reference outside values -- WITH aa AS (SELECT 1 a, 2 b) INSERT INTO withz 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 withz VALUES(1, 'insert') ON CONFLICT (k) DO UPDATE SET v = ' update' WHERE withz.k = (SELECT a FROM aa); WITH aa AS (SELECT 1 a, 2 b) INSERT INTO withz 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 withz 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 withz 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); -- Update a row more than once, in different parts of a wCTE. That is -- an allowed, presumably very rare, edge case, but since it was -- broken in the past, having a test seems worthwhile. WITH simpletup AS ( SELECT 2 k, 'Green' v), upsert_cte AS ( INSERT INTO withz VALUES(2, 'Blue') ON CONFLICT (k) DO UPDATE SET (k, v) = (SELECT k, v FROM simpletup WHERE simpletup.k = withz.k) RETURNING k, v) INSERT INTO withz VALUES(2, 'Red') ON CONFLICT (k) DO UPDATE SET (k, v) = (SELECT k, v FROM upsert_cte WHERE upsert_cte.k = withz.k) RETURNING k, v; DROP TABLE withz; -- WITH referenced by MERGE statement CREATE TABLE m AS SELECT i AS k, (i || ' v')::text v FROM generate_series(1, 16, 3) i; ALTER TABLE m ADD UNIQUE (k); WITH RECURSIVE cte_basic AS (SELECT 1 a, 'cte_basic val' b) MERGE INTO m USING (select 0 k, 'merge source SubPlan' v) o ON m.k=o.k WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_basic WHERE cte_basic.a = m.k LIMIT 1) WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); -- Basic: WITH cte_basic AS MATERIALIZED (SELECT 1 a, 'cte_basic val' b) MERGE INTO m USING (select 0 k, 'merge source SubPlan' v offset 0) o ON m.k=o.k WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_basic WHERE cte_basic.a = m.k LIMIT 1) WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); -- Examine SELECT * FROM m where k = 0; -- See EXPLAIN output for same query: EXPLAIN (VERBOSE, COSTS OFF) WITH cte_basic AS MATERIALIZED (SELECT 1 a, 'cte_basic val' b) MERGE INTO m USING (select 0 k, 'merge source SubPlan' v offset 0) o ON m.k=o.k WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_basic WHERE cte_basic.a = m.k LIMIT 1) WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); -- InitPlan WITH cte_init AS MATERIALIZED (SELECT 1 a, 'cte_init val' b) MERGE INTO m USING (select 1 k, 'merge source InitPlan' v offset 0) o ON m.k=o.k WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_init WHERE a = 1 LIMIT 1) WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); -- Examine SELECT * FROM m where k = 1; -- See EXPLAIN output for same query: EXPLAIN (VERBOSE, COSTS OFF) WITH cte_init AS MATERIALIZED (SELECT 1 a, 'cte_init val' b) MERGE INTO m USING (select 1 k, 'merge source InitPlan' v offset 0) o ON m.k=o.k WHEN MATCHED THEN UPDATE SET v = (SELECT b || ' merge update' FROM cte_init WHERE a = 1 LIMIT 1) WHEN NOT MATCHED THEN INSERT VALUES(o.k, o.v); -- MERGE source comes from CTE: WITH merge_source_cte AS MATERIALIZED (SELECT 15 a, 'merge_source_cte val' b) MERGE INTO m USING (select * from merge_source_cte) o ON m.k=o.a WHEN MATCHED THEN UPDATE SET v = (SELECT b || merge_source_cte.*::text || ' merge update' FROM merge_source_cte WHERE a = 15) WHEN NOT MATCHED THEN INSERT VALUES(o.a, o.b || (SELECT merge_source_cte.*::text || ' merge insert' FROM merge_source_cte)); -- Examine SELECT * FROM m where k = 15; -- See EXPLAIN output for same query: EXPLAIN (VERBOSE, COSTS OFF) WITH merge_source_cte AS MATERIALIZED (SELECT 15 a, 'merge_source_cte val' b) MERGE INTO m USING (select * from merge_source_cte) o ON m.k=o.a WHEN MATCHED THEN UPDATE SET v = (SELECT b || merge_source_cte.*::text || ' merge update' FROM merge_source_cte WHERE a = 15) WHEN NOT MATCHED THEN INSERT VALUES(o.a, o.b || (SELECT merge_source_cte.*::text || ' merge insert' FROM merge_source_cte)); DROP TABLE m; -- check that run to completion happens in proper ordering TRUNCATE TABLE y; INSERT INTO y SELECT generate_series(1, 3); CREATE TEMPORARY TABLE yy (a INTEGER); WITH RECURSIVE t1 AS ( INSERT INTO y SELECT * FROM y RETURNING * ), t2 AS ( INSERT INTO yy SELECT * FROM t1 RETURNING * ) SELECT 1; SELECT * FROM y; SELECT * FROM yy; WITH RECURSIVE t1 AS ( INSERT INTO yy SELECT * FROM t2 RETURNING * ), t2 AS ( INSERT INTO y SELECT * FROM y RETURNING * ) SELECT 1; SELECT * FROM y; SELECT * FROM yy; -- triggers TRUNCATE TABLE y; INSERT INTO y SELECT generate_series(1, 10); CREATE FUNCTION y_trigger() RETURNS trigger AS $$ begin raise notice 'y_trigger: a = %', new.a; return new; end; $$ LANGUAGE plpgsql; CREATE TRIGGER y_trig BEFORE INSERT ON y FOR EACH ROW EXECUTE PROCEDURE y_trigger(); WITH t AS ( INSERT INTO y VALUES (21), (22), (23) RETURNING * ) SELECT * FROM t; SELECT * FROM y; DROP TRIGGER y_trig ON y; CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH ROW EXECUTE PROCEDURE y_trigger(); WITH t AS ( INSERT INTO y VALUES (31), (32), (33) RETURNING * ) SELECT * FROM t LIMIT 1; SELECT * FROM y; DROP TRIGGER y_trig ON y; CREATE OR REPLACE FUNCTION y_trigger() RETURNS trigger AS $$ begin raise notice 'y_trigger'; return null; end; $$ LANGUAGE plpgsql; CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH STATEMENT EXECUTE PROCEDURE y_trigger(); WITH t AS ( INSERT INTO y VALUES (41), (42), (43) RETURNING * ) SELECT * FROM t; SELECT * FROM y; 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; WITH wcte AS ( INSERT INTO child1 VALUES ( 42, 'new' ) RETURNING id AS newid ) UPDATE parent SET id = id + newid FROM wcte; SELECT * FROM parent; WITH rcte AS ( SELECT max(id) AS maxid FROM parent ) DELETE FROM parent USING rcte WHERE id = maxid; SELECT * FROM parent; WITH wcte AS ( INSERT INTO child2 VALUES ( 42, 'new2' ) RETURNING id AS newid ) DELETE FROM parent USING wcte WHERE id = newid; SELECT * FROM parent; -- 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_star USING wcte WHERE aa = q2; -- error cases -- data-modifying WITH tries to use its own output WITH RECURSIVE t AS ( INSERT INTO y SELECT * FROM t ) VALUES(FALSE); -- no RETURNING in a referenced data-modifying WITH WITH t AS ( INSERT INTO y VALUES(0) ) SELECT * FROM t; -- data-modifying WITH allowed only at the top level SELECT * FROM ( WITH t AS (UPDATE y SET a=a+1 RETURNING *) SELECT * FROM t ) ss; -- most variants of rules aren't allowed CREATE RULE y_rule AS ON INSERT TO y WHERE a=0 DO INSTEAD DELETE FROM y; WITH t AS ( INSERT INTO y VALUES(0) ) VALUES(FALSE); CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO INSTEAD NOTHING; WITH t AS ( INSERT INTO y VALUES(0) ) VALUES(FALSE); CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO INSTEAD NOTIFY foo; WITH t AS ( INSERT INTO y VALUES(0) ) VALUES(FALSE); CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO ALSO NOTIFY foo; WITH t AS ( INSERT INTO y VALUES(0) ) VALUES(FALSE); CREATE OR REPLACE RULE y_rule AS ON INSERT TO y DO INSTEAD (NOTIFY foo; NOTIFY bar); WITH t AS ( INSERT INTO y VALUES(0) ) VALUES(FALSE); 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 create table foo (with ordinality); -- fail, WITH is a reserved word with ordinality as (select 1 as x) select * from ordinality; -- check sane response to attempt to modify CTE relation WITH with_test AS (SELECT 42) INSERT INTO with_test VALUES (1); -- check response to attempt to modify table with same name as a CTE (perhaps -- surprisingly it works, because CTEs don't hide tables from data-modifying -- statements) create temp table with_test (i int); with with_test as (select 42) insert into with_test select * from with_test; select * from with_test; drop table with_test;