Current File : //usr/share/mysql-test/r/subquery_bugs.result
#
# Bug#27182010 SUBQUERY INCORRECTLY SHOWS DUPLICATE VALUES ON SUBQUERIES
#
CREATE TABLE p (Id INT,PRIMARY KEY (Id));
INSERT INTO p VALUES (1);
# Test UNIQUE KEY with NULL values
CREATE TABLE s (Id INT, u INT, UNIQUE KEY o(Id, u) );
INSERT INTO s VALUES (1, NULL),(1, NULL);
EXPLAIN SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s WHERE Id=1 AND u IS NULL)ORDER BY Id DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p system PRIMARY NULL NULL NULL 1 NULL
1 SIMPLE s ref o o 10 const,const 1 Using where; Using index; FirstMatch(p)
EXPLAIN SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s WHERE Id=1 AND u IS NOT NULL) ORDER BY Id DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p system PRIMARY NULL NULL NULL 1 NULL
1 SIMPLE s ref o o 5 const 1 Using where; Using index; FirstMatch(p)
SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s WHERE Id=1 AND u IS NULL)ORDER BY Id DESC;
Id
1
SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s WHERE Id=1 AND u IS NOT NULL) ORDER BY Id DESC;
Id
# UNIQUE KEY without NULL values
CREATE TABLE s1 (Id INT, u INT, UNIQUE KEY o(Id, u) );
INSERT INTO s1 VALUES (1, 2),(1, 3);
EXPLAIN SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s1.Id FROM s1 WHERE Id=1 AND u IS NOT NULL) ORDER BY Id DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p system PRIMARY NULL NULL NULL 1 NULL
1 SIMPLE s1 ref o o 5 const 1 Using where; Using index; FirstMatch(p)
EXPLAIN SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s1.Id FROM s1 WHERE Id=1 AND u != 1) ORDER BY Id DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p system PRIMARY NULL NULL NULL 1 NULL
1 SIMPLE s1 ref o o 5 const 1 Using where; Using index; FirstMatch(p)
SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s1.Id FROM s1 WHERE Id=1 AND u IS NOT NULL) ORDER BY Id DESC;
Id
1
SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s1.Id FROM s1 WHERE Id=1 AND u != 1) ORDER BY Id DESC;
Id
1
# NON UNIQUE KEY Scenario
CREATE TABLE s2 (Id INT, u INT, KEY o(Id, u) );
INSERT INTO s2 VALUES (1, NULL),(1, NULL);
#UNIQUE KEY with NON NULL FIELDS
CREATE TABLE s3 (Id INT NOT NULL, u INT NOT NULL, UNIQUE KEY o(Id, u));
INSERT INTO s3 VALUES (1, 2),(1, 3);
EXPLAIN SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s2 s WHERE Id=1 AND u IS NULL) ORDER BY Id DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p system PRIMARY NULL NULL NULL 1 NULL
1 SIMPLE s ref o o 10 const,const 1 Using where; Using index; FirstMatch(p)
EXPLAIN SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s3 s WHERE Id=1 AND u IS NOT NULL)
ORDER BY Id DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p system PRIMARY NULL NULL NULL 1 NULL
1 SIMPLE s ref o o 4 const 1 Using where; Using index; FirstMatch(p)
SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s2 s WHERE Id=1 AND u IS NULL) ORDER BY Id DESC;
Id
1
SELECT p.Id FROM (p) WHERE p.Id IN (
SELECT s.Id FROM s3 s WHERE Id=1 AND u IS NOT NULL)
ORDER BY Id DESC;
Id
1
DROP TABLE p, s, s1, s2, s3;
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