--- /dev/null
+QUERY: SELECT 1 AS one WHERE 1 IN (SELECT 1);
+one
+---
+ 1
+(1 row)
+
+QUERY: SELECT 1 AS zero WHERE 1 NOT IN (SELECT 1);
+zero
+----
+(0 rows)
+
+QUERY: SELECT 1 AS zero WHERE 1 IN (SELECT 2);
+zero
+----
+(0 rows)
+
+QUERY: CREATE TABLE SUBSELECT_TBL (
+ f1 integer,
+ f2 integer,
+ f3 float
+);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (1, 2, 3);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (2, 3, 4);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (3, 4, 5);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (1, 1, 1);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (2, 2, 2);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (3, 3, 3);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (6, 7, 8);
+QUERY: INSERT INTO SUBSELECT_TBL VALUES (8, 9, NULL);
+QUERY: SELECT '' AS eight, * FROM SUBSELECT_TBL;
+eight|f1|f2|f3
+-----+--+--+--
+ | 1| 2| 3
+ | 2| 3| 4
+ | 3| 4| 5
+ | 1| 1| 1
+ | 2| 2| 2
+ | 3| 3| 3
+ | 6| 7| 8
+ | 8| 9|
+(8 rows)
+
+QUERY: SELECT '' AS two, f1 AS "Constant Select" FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT 1);
+two|Constant Select
+---+---------------
+ | 1
+ | 1
+(2 rows)
+
+QUERY: SELECT '' AS six, f1 AS "Uncorrelated Field" FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL);
+six|Uncorrelated Field
+---+------------------
+ | 1
+ | 2
+ | 3
+ | 1
+ | 2
+ | 3
+(6 rows)
+
+QUERY: SELECT '' AS six, f1 AS "Uncorrelated Field" FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE
+ f2 IN (SELECT f1 FROM SUBSELECT_TBL));
+six|Uncorrelated Field
+---+------------------
+ | 1
+ | 2
+ | 3
+ | 1
+ | 2
+ | 3
+(6 rows)
+
+QUERY: SELECT '' AS six, f1 AS "Correlated Field", f3 AS "Second Field"
+ FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE f2 = f1);
+six|Correlated Field|Second Field
+---+----------------+------------
+ | 1| 3
+ | 2| 4
+ | 3| 5
+ | 1| 1
+ | 2| 2
+ | 3| 3
+(6 rows)
+
+QUERY: SELECT '' AS six, f1 AS "Correlated Field", f3 AS "Second Field"
+ FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE CAST(f2 AS float) = f3);
+six|Correlated Field|Second Field
+---+----------------+------------
+ | 1| 3
+ | 2| 4
+ | 3| 5
+ | 1| 1
+ | 2| 2
+ | 3| 3
+(6 rows)
+
+QUERY: SELECT '' AS six, f1 AS "Correlated Field", f3 AS "Second Field"
+ FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE f2 = CAST(f3 AS integer));
+ERROR: dtoi4: unable to convert null
+QUERY: SELECT '' AS five, f1 AS "Correlated Field"
+ FROM SUBSELECT_TBL
+ WHERE (f1, f2) IN (SELECT f2, CAST(f3 AS int4) FROM SUBSELECT_TBL WHERE f3 IS NOT NULL);
+five|Correlated Field
+----+----------------
+ | 2
+ | 3
+ | 1
+ | 2
+ | 3
+(5 rows)
+
+QUERY: SELECT '' AS three, f1 AS "Correlated Field"
+ FROM SUBSELECT_TBL
+ WHERE (f1, f2) NOT IN (SELECT f2, CAST(f3 AS int4) FROM SUBSELECT_TBL WHERE f3 IS NOT NULL);
+three|Correlated Field
+-----+----------------
+ | 1
+ | 6
+ | 8
+(3 rows)
+
+QUERY: SELECT '' AS eight, ss.f1 AS "Correlated Field", ss.f3 AS "Second Field"
+ FROM SUBSELECT_TBL ss
+ WHERE f1 NOT IN (SELECT f1 FROM INT4_TBL WHERE f1 != ss.f1);
+eight|Correlated Field|Second Field
+-----+----------------+------------
+ | 1| 3
+ | 2| 4
+ | 3| 5
+ | 1| 1
+ | 2| 2
+ | 3| 3
+ | 6| 8
+ | 8|
+(8 rows)
+
--- /dev/null
+--
+-- Subselects
+--
+
+SELECT 1 AS one WHERE 1 IN (SELECT 1);
+
+SELECT 1 AS zero WHERE 1 NOT IN (SELECT 1);
+
+SELECT 1 AS zero WHERE 1 IN (SELECT 2);
+
+-- Set up some simple test tables
+
+CREATE TABLE SUBSELECT_TBL (
+ f1 integer,
+ f2 integer,
+ f3 float
+);
+
+INSERT INTO SUBSELECT_TBL VALUES (1, 2, 3);
+INSERT INTO SUBSELECT_TBL VALUES (2, 3, 4);
+INSERT INTO SUBSELECT_TBL VALUES (3, 4, 5);
+INSERT INTO SUBSELECT_TBL VALUES (1, 1, 1);
+INSERT INTO SUBSELECT_TBL VALUES (2, 2, 2);
+INSERT INTO SUBSELECT_TBL VALUES (3, 3, 3);
+INSERT INTO SUBSELECT_TBL VALUES (6, 7, 8);
+INSERT INTO SUBSELECT_TBL VALUES (8, 9, NULL);
+
+SELECT '' AS eight, * FROM SUBSELECT_TBL;
+
+-- Uncorrelated subselects
+
+SELECT '' AS two, f1 AS "Constant Select" FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT 1);
+
+SELECT '' AS six, f1 AS "Uncorrelated Field" FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL);
+
+SELECT '' AS six, f1 AS "Uncorrelated Field" FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE
+ f2 IN (SELECT f1 FROM SUBSELECT_TBL));
+
+-- Correlated subselects
+
+SELECT '' AS six, f1 AS "Correlated Field", f3 AS "Second Field"
+ FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE f2 = f1);
+
+SELECT '' AS six, f1 AS "Correlated Field", f3 AS "Second Field"
+ FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE CAST(f2 AS float) = f3);
+
+SELECT '' AS six, f1 AS "Correlated Field", f3 AS "Second Field"
+ FROM SUBSELECT_TBL
+ WHERE f1 IN (SELECT f2 FROM SUBSELECT_TBL WHERE f2 = CAST(f3 AS integer));
+
+SELECT '' AS five, f1 AS "Correlated Field"
+ FROM SUBSELECT_TBL
+ WHERE (f1, f2) IN (SELECT f2, CAST(f3 AS int4) FROM SUBSELECT_TBL WHERE f3 IS NOT NULL);
+
+SELECT '' AS three, f1 AS "Correlated Field"
+ FROM SUBSELECT_TBL
+ WHERE (f1, f2) NOT IN (SELECT f2, CAST(f3 AS int4) FROM SUBSELECT_TBL WHERE f3 IS NOT NULL);
+
+--
+-- Use some existing tables in the regression test
+--
+
+SELECT '' AS eight, ss.f1 AS "Correlated Field", ss.f3 AS "Second Field"
+ FROM SUBSELECT_TBL ss
+ WHERE f1 NOT IN (SELECT f1 FROM INT4_TBL WHERE f1 != ss.f1);
+