-- -- JOIN -- Test JOIN clauses -- CREATE TABLE J1_TBL ( i integer, j integer, t text ); CREATE TABLE J2_TBL ( i integer, k integer ); INSERT INTO J1_TBL VALUES (1, 4, 'one'); INSERT INTO J1_TBL VALUES (2, 3, 'two'); INSERT INTO J1_TBL VALUES (3, 2, 'three'); INSERT INTO J1_TBL VALUES (4, 1, 'four'); INSERT INTO J1_TBL VALUES (5, 0, 'five'); INSERT INTO J1_TBL VALUES (6, 6, 'six'); INSERT INTO J1_TBL VALUES (7, 7, 'seven'); INSERT INTO J1_TBL VALUES (8, 8, 'eight'); INSERT INTO J1_TBL VALUES (0, NULL, 'zero'); INSERT INTO J1_TBL VALUES (NULL, NULL, 'null'); INSERT INTO J1_TBL VALUES (NULL, 0, 'zero'); INSERT INTO J2_TBL VALUES (1, -1); INSERT INTO J2_TBL VALUES (2, 2); INSERT INTO J2_TBL VALUES (3, -3); INSERT INTO J2_TBL VALUES (2, 4); INSERT INTO J2_TBL VALUES (5, -5); INSERT INTO J2_TBL VALUES (5, -5); INSERT INTO J2_TBL VALUES (0, NULL); INSERT INTO J2_TBL VALUES (NULL, NULL); INSERT INTO J2_TBL VALUES (NULL, 0); -- -- CORRELATION NAMES -- Make sure that table/column aliases are supported -- before diving into more complex join syntax. -- SELECT '' AS "xxx", * FROM J1_TBL AS tx; SELECT '' AS "xxx", * FROM J1_TBL tx; SELECT '' AS "xxx", * FROM J1_TBL AS t1 (a, b, c); SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b, c); SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b, c), J2_TBL t2 (d, e); SELECT '' AS "xxx", t1.a, t2.e FROM J1_TBL t1 (a, b, c), J2_TBL t2 (d, e) WHERE t1.a = t2.d; -- -- CROSS JOIN -- Qualifications are not allowed on cross joins, -- which degenerate into a standard unqualified inner join. -- SELECT '' AS "xxx", * FROM J1_TBL CROSS JOIN J2_TBL; -- ambiguous column SELECT '' AS "xxx", i, k, t FROM J1_TBL CROSS JOIN J2_TBL; -- resolve previous ambiguity by specifying the table name SELECT '' AS "xxx", t1.i, k, t FROM J1_TBL t1 CROSS JOIN J2_TBL t2; SELECT '' AS "xxx", ii, tt, kk FROM (J1_TBL CROSS JOIN J2_TBL) AS tx (ii, jj, tt, ii2, kk); SELECT '' AS "xxx", tx.ii, tx.jj, tx.kk FROM (J1_TBL t1 (a, b, c) CROSS JOIN J2_TBL t2 (d, e)) AS tx (ii, jj, tt, ii2, kk); SELECT '' AS "xxx", * FROM J1_TBL CROSS JOIN J2_TBL a CROSS JOIN J2_TBL b; -- -- -- Inner joins (equi-joins) -- -- -- -- Inner joins (equi-joins) with USING clause -- The USING syntax changes the shape of the resulting table -- by including a column in the USING clause only once in the result. -- -- Inner equi-join on specified column SELECT '' AS "xxx", * FROM J1_TBL INNER JOIN J2_TBL USING (i); -- Same as above, slightly different syntax SELECT '' AS "xxx", * FROM J1_TBL JOIN J2_TBL USING (i); SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b, c) JOIN J2_TBL t2 (a, d) USING (a) ORDER BY a, d; SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b, c) JOIN J2_TBL t2 (a, b) USING (b) ORDER BY b, t1.a; -- -- NATURAL JOIN -- Inner equi-join on all columns with the same name -- SELECT '' AS "xxx", * FROM J1_TBL NATURAL JOIN J2_TBL; SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b, c) NATURAL JOIN J2_TBL t2 (a, d); SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b, c) NATURAL JOIN J2_TBL t2 (d, a); -- mismatch number of columns -- currently, Postgres will fill in with underlying names SELECT '' AS "xxx", * FROM J1_TBL t1 (a, b) NATURAL JOIN J2_TBL t2 (a); -- -- Inner joins (equi-joins) -- SELECT '' AS "xxx", * FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i = J2_TBL.i); SELECT '' AS "xxx", * FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i = J2_TBL.k); -- -- Non-equi-joins -- SELECT '' AS "xxx", * FROM J1_TBL JOIN J2_TBL ON (J1_TBL.i <= J2_TBL.k); -- -- Outer joins -- Note that OUTER is a noise word -- SELECT '' AS "xxx", * FROM J1_TBL LEFT OUTER JOIN J2_TBL USING (i) ORDER BY i, k, t; SELECT '' AS "xxx", * FROM J1_TBL LEFT JOIN J2_TBL USING (i) ORDER BY i, k, t; SELECT '' AS "xxx", * FROM J1_TBL RIGHT OUTER JOIN J2_TBL USING (i); SELECT '' AS "xxx", * FROM J1_TBL RIGHT JOIN J2_TBL USING (i); SELECT '' AS "xxx", * FROM J1_TBL FULL OUTER JOIN J2_TBL USING (i) ORDER BY i, k, t; SELECT '' AS "xxx", * FROM J1_TBL FULL JOIN J2_TBL USING (i) ORDER BY i, k, t; SELECT '' AS "xxx", * FROM J1_TBL LEFT JOIN J2_TBL USING (i) WHERE (k = 1); SELECT '' AS "xxx", * FROM J1_TBL LEFT JOIN J2_TBL USING (i) WHERE (i = 1); -- -- More complicated constructs -- -- -- Multiway full join -- CREATE TABLE t1 (name TEXT, n INTEGER); CREATE TABLE t2 (name TEXT, n INTEGER); CREATE TABLE t3 (name TEXT, n INTEGER); INSERT INTO t1 VALUES ( 'bb', 11 ); INSERT INTO t2 VALUES ( 'bb', 12 ); INSERT INTO t2 VALUES ( 'cc', 22 ); INSERT INTO t2 VALUES ( 'ee', 42 ); INSERT INTO t3 VALUES ( 'bb', 13 ); INSERT INTO t3 VALUES ( 'cc', 23 ); INSERT INTO t3 VALUES ( 'dd', 33 ); SELECT * FROM t1 FULL JOIN t2 USING (name) FULL JOIN t3 USING (name); -- -- Test interactions of join syntax and subqueries -- -- Basic cases (we expect planner to pull up the subquery here) SELECT * FROM (SELECT * FROM t2) as s2 INNER JOIN (SELECT * FROM t3) s3 USING (name); SELECT * FROM (SELECT * FROM t2) as s2 LEFT JOIN (SELECT * FROM t3) s3 USING (name); SELECT * FROM (SELECT * FROM t2) as s2 FULL JOIN (SELECT * FROM t3) s3 USING (name); -- Cases with non-nullable expressions in subquery results; -- make sure these go to null as expected SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL INNER JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL LEFT JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; SELECT * FROM (SELECT name, n as s1_n, 1 as s1_1 FROM t1) as s1 NATURAL INNER JOIN (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL INNER JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; SELECT * FROM (SELECT name, n as s1_n, 1 as s1_1 FROM t1) as s1 NATURAL FULL JOIN (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n, 3 as s3_2 FROM t3) s3; SELECT * FROM (SELECT name, n as s1_n FROM t1) as s1 NATURAL FULL JOIN (SELECT * FROM (SELECT name, n as s2_n FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n FROM t3) as s3 ) ss2; SELECT * FROM (SELECT name, n as s1_n FROM t1) as s1 NATURAL FULL JOIN (SELECT * FROM (SELECT name, n as s2_n, 2 as s2_2 FROM t2) as s2 NATURAL FULL JOIN (SELECT name, n as s3_n FROM t3) as s3 ) ss2; -- Test for propagation of nullability constraints into sub-joins create temp table x (x1 int, x2 int); insert into x values (1,11); insert into x values (2,22); insert into x values (3,null); insert into x values (4,44); insert into x values (5,null); create temp table y (y1 int, y2 int); insert into y values (1,111); insert into y values (2,222); insert into y values (3,333); insert into y values (4,null); select * from x; select * from y; select * from x left join y on (x1 = y1 and x2 is not null); select * from x left join y on (x1 = y1 and y2 is not null); select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1); select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1 and x2 is not null); select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1 and y2 is not null); select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1 and xx2 is not null); -- these should NOT give the same answers as above select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1) where (x2 is not null); select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1) where (y2 is not null); select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2) on (x1 = xx1) where (xx2 is not null); -- -- regression test: check for bug with propagation of implied equality -- to outside an IN -- select count(*) from tenk1 a where unique1 in (select unique1 from tenk1 b join tenk1 c using (unique1) where b.unique2 = 42); -- -- regression test: check for failure to generate a plan with multiple -- degenerate IN clauses -- select count(*) from tenk1 x where x.unique1 in (select a.f1 from int4_tbl a,float8_tbl b where a.f1=b.f1) and x.unique1 = 0 and x.unique1 in (select aa.f1 from int4_tbl aa,float8_tbl bb where aa.f1=bb.f1); -- try that with GEQO too begin; set geqo = on; set geqo_threshold = 2; select count(*) from tenk1 x where x.unique1 in (select a.f1 from int4_tbl a,float8_tbl b where a.f1=b.f1) and x.unique1 = 0 and x.unique1 in (select aa.f1 from int4_tbl aa,float8_tbl bb where aa.f1=bb.f1); rollback; -- -- Clean up -- DROP TABLE t1; DROP TABLE t2; DROP TABLE t3; DROP TABLE J1_TBL; DROP TABLE J2_TBL; -- Both DELETE and UPDATE allow the specification of additional tables -- to "join" against to determine which rows should be modified. CREATE TEMP TABLE t1 (a int, b int); CREATE TEMP TABLE t2 (a int, b int); CREATE TEMP TABLE t3 (x int, y int); INSERT INTO t1 VALUES (5, 10); INSERT INTO t1 VALUES (15, 20); INSERT INTO t1 VALUES (100, 100); INSERT INTO t1 VALUES (200, 1000); INSERT INTO t2 VALUES (200, 2000); INSERT INTO t3 VALUES (5, 20); INSERT INTO t3 VALUES (6, 7); INSERT INTO t3 VALUES (7, 8); INSERT INTO t3 VALUES (500, 100); DELETE FROM t3 USING t1 table1 WHERE t3.x = table1.a; SELECT * FROM t3; DELETE FROM t3 USING t1 JOIN t2 USING (a) WHERE t3.x > t1.a; SELECT * FROM t3; DELETE FROM t3 USING t3 t3_other WHERE t3.x = t3_other.x AND t3.y = t3_other.y; SELECT * FROM t3; -- Test join against inheritance tree create temp table t2a () inherits (t2); insert into t2a values (200, 2001); select * from t1 left join t2 on (t1.a = t2.a); -- -- regression test for 8.1 merge right join bug -- CREATE TEMP TABLE tt1 ( tt1_id int4, joincol int4 ); INSERT INTO tt1 VALUES (1, 11); INSERT INTO tt1 VALUES (2, NULL); CREATE TEMP TABLE tt2 ( tt2_id int4, joincol int4 ); INSERT INTO tt2 VALUES (21, 11); INSERT INTO tt2 VALUES (22, 11); set enable_hashjoin to off; set enable_nestloop to off; -- these should give the same results select tt1.*, tt2.* from tt1 left join tt2 on tt1.joincol = tt2.joincol; select tt1.*, tt2.* from tt2 right join tt1 on tt1.joincol = tt2.joincol; reset enable_hashjoin; reset enable_nestloop; -- -- regression test for 8.2 bug with improper re-ordering of left joins -- create temp table tt3(f1 int, f2 text); insert into tt3 select x, repeat('xyzzy', 100) from generate_series(1,10000) x; create index tt3i on tt3(f1); analyze tt3; create temp table tt4(f1 int); insert into tt4 values (0),(1),(9999); analyze tt4; SELECT a.f1 FROM tt4 a LEFT JOIN ( SELECT b.f1 FROM tt3 b LEFT JOIN tt3 c ON (b.f1 = c.f1) WHERE c.f1 IS NULL ) AS d ON (a.f1 = d.f1) WHERE d.f1 IS NULL; -- -- regression test for problems of the sort depicted in bug #3494 -- create temp table tt5(f1 int, f2 int); create temp table tt6(f1 int, f2 int); insert into tt5 values(1, 10); insert into tt5 values(1, 11); insert into tt6 values(1, 9); insert into tt6 values(1, 2); insert into tt6 values(2, 9); select * from tt5,tt6 where tt5.f1 = tt6.f1 and tt5.f1 = tt5.f2 - tt6.f2; -- -- regression test for problems of the sort depicted in bug #3588 -- create temp table xx (pkxx int); create temp table yy (pkyy int, pkxx int); insert into xx values (1); insert into xx values (2); insert into xx values (3); insert into yy values (101, 1); insert into yy values (201, 2); insert into yy values (301, NULL); select yy.pkyy as yy_pkyy, yy.pkxx as yy_pkxx, yya.pkyy as yya_pkyy, xxa.pkxx as xxa_pkxx, xxb.pkxx as xxb_pkxx from yy left join (SELECT * FROM yy where pkyy = 101) as yya ON yy.pkyy = yya.pkyy left join xx xxa on yya.pkxx = xxa.pkxx left join xx xxb on coalesce (xxa.pkxx, 1) = xxb.pkxx; -- -- regression test for improper pushing of constants across outer-join clauses -- (as seen in early 8.2.x releases) -- create temp table zt1 (f1 int primary key); create temp table zt2 (f2 int primary key); create temp table zt3 (f3 int primary key); insert into zt1 values(53); insert into zt2 values(53); select * from zt2 left join zt3 on (f2 = f3) left join zt1 on (f3 = f1) where f2 = 53; create temp view zv1 as select *,'dummy'::text AS junk from zt1; select * from zt2 left join zt3 on (f2 = f3) left join zv1 on (f3 = f1) where f2 = 53; -- -- regression test for improper extraction of OR indexqual conditions -- (as seen in early 8.3.x releases) -- select a.unique2, a.ten, b.tenthous, b.unique2, b.hundred from tenk1 a left join tenk1 b on a.unique2 = b.tenthous where a.unique1 = 42 and ((b.unique2 is null and a.ten = 2) or b.hundred = 3); -- -- test proper positioning of one-time quals in EXISTS (8.4devel bug) -- prepare foo(bool) as select count(*) from tenk1 a left join tenk1 b on (a.unique2 = b.unique1 and exists (select 1 from tenk1 c where c.thousand = b.unique2 and $1)); execute foo(true); execute foo(false); -- -- test for sane behavior with noncanonical merge clauses, per bug #4926 -- begin; set enable_mergejoin = 1; set enable_hashjoin = 0; set enable_nestloop = 0; create temp table a (i integer); create temp table b (x integer, y integer); select * from a left join b on i = x and i = y and x = i; rollback; -- -- test NULL behavior of whole-row Vars, per bug #5025 -- select t1.q2, count(t2.*) from int8_tbl t1 left join int8_tbl t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; select t1.q2, count(t2.*) from int8_tbl t1 left join (select * from int8_tbl) t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; select t1.q2, count(t2.*) from int8_tbl t1 left join (select * from int8_tbl offset 0) t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; select t1.q2, count(t2.*) from int8_tbl t1 left join (select q1, case when q2=1 then 1 else q2 end as q2 from int8_tbl) t2 on (t1.q2 = t2.q1) group by t1.q2 order by 1; -- -- test the corner cases FULL JOIN ON TRUE and FULL JOIN ON FALSE -- select * from int4_tbl a full join int4_tbl b on true; select * from int4_tbl a full join int4_tbl b on false; -- -- test join removal -- create temp table parent (k int primary key, pd int); create temp table child (k int unique, cd int); insert into parent values (1, 10), (2, 20), (3, 30); insert into child values (1, 100), (4, 400); -- this case is optimizable select p.* from parent p left join child c on (p.k = c.k); explain (costs off) select p.* from parent p left join child c on (p.k = c.k); -- this case is not select p.*, linked from parent p left join (select c.*, true as linked from child c) as ss on (p.k = ss.k); explain (costs off) select p.*, linked from parent p left join (select c.*, true as linked from child c) as ss on (p.k = ss.k);