change test_if_equality_guarantees_uniqueness()

from an ad hoc set of limitations
to a correct rule

1 files changed, 26 insertions, 0 deletions

diff --git a/mysql-test/r/distinct.result b/mysql-test/r/distinct.result
index fdd26d7e543..eafd16440b0 100644
--- a/mysql-test/r/distinct.result
+++ b/mysql-test/r/distinct.result
@@ -804,6 +804,32 @@ select distinct a from t1 where a = DATE('2010-10-10');
 a
 2010-10-10
 20101010
+explain select distinct a from t1 where a = DATE('2010-10-10');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Using temporary
+drop table t1;
+# date = string
+create table t1 (a date);
+insert t1 values ('2010-10-10'), ('20101010');
+explain select distinct a from t1 where a = '2010-10-10';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+drop table t1;
+# double = string
+create table t1 (a double);
+insert t1 values (2), (2);
+explain select distinct a from t1 where a = '2';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+# double = int
+explain select distinct a from t1 where a = 2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+# string = double
+alter table t1 modify a varchar(100);
+explain select distinct a from t1 where a = 2e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Using temporary
 drop table t1;
 create table t1 (f1 varchar(40));
 insert into t1 values ('2010-10-10 00:00:00.0001'),('2010-10-10 00:00:00.0002'),('2010-10-10 00:00:00.0003');