Fixed bug #5500: EXPLAIN returned a wrong select_type for queries using views.

Select_type in the EXPLAIN output for the query SELECT * FROM t1 was
'SIMPLE', while for the query SELECT * FROM v1, where the view v1
was defined as SELECT * FROM t1, the EXPLAIN output contained 'PRIMARY'
for the select_type column.
 

mysql-test/r/group_by.result

@@ -807,8 +807,8 @@ explain
 SELECT straight_join sql_no_cache v1.a, v1.b, v1.real_b from t2, v1
 where t2.b=v1.a GROUP BY t2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	index	b	b	2	NULL	10	Using index
-1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	1	test.t2.b	1	
+1	SIMPLE	t2	index	b	b	2	NULL	10	Using index
+1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	1	test.t2.b	1	
 SELECT straight_join sql_no_cache v1.a, v1.b, v1.real_b from t2, v1
 where t2.b=v1.a GROUP BY t2.b;
 a	b	real_b

mysql-test/r/information_schema.result

@@ -337,7 +337,7 @@ mysql
 test
 explain select * from v0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	#	ALL	NULL	NULL	NULL	NULL	2	
+1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	2	
 create view v1 (c) as select table_name from information_schema.tables
 where table_name="v1";
 select * from v1;

mysql-test/r/olap.result

@@ -611,7 +611,7 @@ C
 NULL
 EXPLAIN SELECT type FROM v1 GROUP BY type WITH ROLLUP;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using filesort
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	Using filesort
 DROP VIEW v1;
 DROP TABLE t1;
 CREATE TABLE t1 (a int(11) NOT NULL);

mysql-test/r/range.result

@@ -750,13 +750,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index
 EXPLAIN SELECT a,b FROM v1 WHERE a < 2 and b=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index
+1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index
 EXPLAIN SELECT a,b FROM t1 WHERE a < 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index
 EXPLAIN SELECT a,b FROM v1 WHERE a < 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index
+1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index
 SELECT a,b FROM t1 WHERE a < 2 and b=3;
 a	b
 1	3
@@ -799,13 +799,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	PRIMARY	PRIMARY	8	NULL	#	Using where; Using index
 explain select * from v1 where a in (3,4)  and b in (1,2,3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	PRIMARY	PRIMARY	8	NULL	#	Using where; Using index
+1	SIMPLE	t1	range	PRIMARY	PRIMARY	8	NULL	#	Using where; Using index
 explain select * from t1 where a between 3 and 4 and b between 1 and 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	PRIMARY	PRIMARY	8	NULL	#	Using where; Using index
 explain select * from v1 where a between 3 and 4 and b between 1 and 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	PRIMARY	PRIMARY	8	NULL	#	Using where; Using index
+1	SIMPLE	t1	range	PRIMARY	PRIMARY	8	NULL	#	Using where; Using index
 drop view v1;
 drop table t1;
 create table t3 (a int);

mysql-test/r/view.result

@@ -49,7 +49,7 @@ select v1.b from v1;
 ERROR 42S22: Unknown column 'v1.b' in 'field list'
 explain extended select c from v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	
 Warnings:
 Note	1003	select (`test`.`t1`.`b` + 1) AS `c` from `test`.`t1`
 create algorithm=temptable view v2 (c) as select b+1 from t1;
@@ -83,7 +83,7 @@ c
 12
 explain extended select c from v3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	
 Warnings:
 Note	1003	select ((`test`.`t1`.`b` + 1) + 1) AS `c` from `test`.`t1`
 create algorithm=temptable view v4 (c) as select c+1 from v2;
@@ -376,7 +376,7 @@ c
 30
 explain extended select * from v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`b` AS `c` from `test`.`t1` where (`test`.`t1`.`a` < 3)
 update v1 set c=c+1;
@@ -1391,9 +1391,9 @@ a	a	b
 4	NULL	NULL
 explain extended select * from t3 left join v3 on (t3.a = v3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	
 Warnings:
 Note	1003	select `test`.`t3`.`a` AS `a`,`test`.`t1`.`a` AS `a`,`test`.`t2`.`a` AS `b` from `test`.`t3` left join (`test`.`t1` left join `test`.`t2` on((`test`.`t1`.`a` = `test`.`t2`.`a`))) on((`test`.`t3`.`a` = `test`.`t1`.`a`)) where 1
 create view v1 (a) as select a from t1;
@@ -1406,9 +1406,9 @@ a	a	b
 4	NULL	NULL
 explain extended select * from t3 left join v4 on (t3.a = v4.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	
 Warnings:
 Note	1003	select `test`.`t3`.`a` AS `a`,`test`.`t1`.`a` AS `a`,`test`.`t2`.`a` AS `b` from `test`.`t3` left join (`test`.`t1` left join (`test`.`t2`) on((`test`.`t1`.`a` = `test`.`t2`.`a`))) on((`test`.`t3`.`a` = `test`.`t1`.`a`)) where 1
 prepare stmt1 from "select * from t3 left join v4 on (t3.a = v4.a);";
@@ -2321,12 +2321,12 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	a	a	10	const,test.t1.b	2	Using where; Using index
 EXPLAIN SELECT * FROM v1 WHERE a=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-1	PRIMARY	t2	ref	a	a	10	const,test.t1.b	2	Using where; Using index
+1	SIMPLE	t1	ref	a	a	5	const	1	Using where; Using index
+1	SIMPLE	t2	ref	a	a	10	const,test.t1.b	2	Using where; Using index
 EXPLAIN SELECT * FROM v2 WHERE a=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t1	ref	a	a	5	const	1	Using where; Using index
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
 DROP VIEW v1,v2;
 DROP TABLE t1,t2,t3;
 create table t1 (f1 int);
@@ -2409,7 +2409,7 @@ insert into t1 values (1),(2);
 create view v1 as select * from t1;
 explain select id from v1 order by id;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	2	Using index
+1	SIMPLE	t1	index	NULL	PRIMARY	4	NULL	2	Using index
 drop view v1;
 drop table t1;
 create table t1(f1 int, f2 int);
@@ -2480,7 +2480,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 EXPLAIN SELECT MAX(a) FROM v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 SELECT MIN(a) FROM t1;
 MIN(a)
 0
@@ -2492,7 +2492,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 EXPLAIN SELECT MIN(a) FROM v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 DROP VIEW v1;
 DROP TABLE t1;
 CREATE TABLE t1 (x varchar(10));
@@ -2879,3 +2879,22 @@ View	Create View
 v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select `t1`.`f1` AS `f1` from `t1` where (`t1`.`f1` between now() and (now() + interval 1 minute))
 drop view v1;
 drop table t1;
+CREATE TABLE t1 (s1 int);
+CREATE VIEW v1 AS SELECT * FROM t1;
+EXPLAIN SELECT * FROM t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+EXPLAIN SELECT * FROM v1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+INSERT INTO t1 VALUES (1), (3), (2);
+EXPLAIN SELECT * FROM t1 t WHERE t.s1+1 < (SELECT MAX(t1.s1) FROM t1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t	ALL	NULL	NULL	NULL	NULL	3	Using where
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
+EXPLAIN SELECT * FROM v1 t WHERE t.s1+1 < (SELECT MAX(t1.s1) FROM t1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
+DROP VIEW v1;
+DROP TABLE t1;

mysql-test/r/view_grant.result

@@ -103,7 +103,7 @@ ERROR 42000: SHOW VIEW command denied to user 'mysqltest_1'@'localhost' for tabl
 grant select on mysqltest.t1 to mysqltest_1@localhost;
 explain select c from mysqltest.v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
 show create view mysqltest.v1;
 ERROR 42000: SHOW VIEW command denied to user 'mysqltest_1'@'localhost' for table 'v1'
 explain select c from mysqltest.v2;
@@ -123,7 +123,7 @@ ERROR 42000: SHOW VIEW command denied to user 'mysqltest_1'@'localhost' for tabl
 grant show view on mysqltest.* to mysqltest_1@localhost;
 explain select c from mysqltest.v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
 show create view mysqltest.v1;
 View	Create View
 v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `mysqltest`.`v1` AS select (`mysqltest`.`t1`.`a` + 1) AS `c`,(`mysqltest`.`t1`.`b` + 1) AS `d` from `mysqltest`.`t1`
@@ -136,7 +136,7 @@ View	Create View
 v2	CREATE ALGORITHM=TEMPTABLE DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `mysqltest`.`v2` AS select (`mysqltest`.`t1`.`a` + 1) AS `c`,(`mysqltest`.`t1`.`b` + 1) AS `d` from `mysqltest`.`t1`
 explain select c from mysqltest.v3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+1	SIMPLE	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 show create view mysqltest.v3;
 View	Create View
 v3	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `mysqltest`.`v3` AS select (`mysqltest`.`t2`.`a` + 1) AS `c`,(`mysqltest`.`t2`.`b` + 1) AS `d` from `mysqltest`.`t2`

mysql-test/t/view.test

@@ -2760,3 +2760,21 @@ create view v1 as select * from t1 where f1 between now() and now() + interval 1
 show create view v1;
 drop view v1;
 drop table t1;
+
+#
+# Bug #5500: wrong select_type in EXPLAIN output for queries over views
+#
+
+CREATE TABLE t1 (s1 int); 
+CREATE VIEW v1 AS SELECT * FROM t1;
+
+EXPLAIN SELECT * FROM t1;
+EXPLAIN SELECT * FROM v1;
+
+INSERT INTO t1 VALUES (1), (3), (2);
+
+EXPLAIN SELECT * FROM t1 t WHERE t.s1+1 < (SELECT MAX(t1.s1) FROM t1); 
+EXPLAIN SELECT * FROM v1 t WHERE t.s1+1 < (SELECT MAX(t1.s1) FROM t1); 
+
+DROP VIEW v1;
+DROP TABLE t1;

sql/sql_select.cc

@@ -14221,9 +14221,12 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
 	item_list.push_back(new Item_string(table_name_buffer, len, cs));
       }
       else
-	item_list.push_back(new Item_string(table->alias,
-					    strlen(table->alias),
+      {
+        TABLE_LIST *tab=table->pos_in_table_list; 
+	item_list.push_back(new Item_string(tab->alias,
+					    strlen(tab->alias),
 					    cs));
+      }
       /* type */
       item_list.push_back(new Item_string(join_type_str[tab->type],
 					  strlen(join_type_str[tab->type]),
@@ -14410,8 +14413,8 @@ bool mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
     // drop UNCACHEABLE_EXPLAIN, because it is for internal usage only
     uint8 uncacheable= (sl->uncacheable & ~UNCACHEABLE_EXPLAIN);
     sl->type= (((&thd->lex->select_lex)==sl)?
-	       ((thd->lex->all_selects_list != sl) ? 
-		primary_key_name : "SIMPLE"):
+	       (sl->first_inner_unit() || sl->next_select() ? 
+		"PRIMARY" : "SIMPLE"):
 	       ((sl == first)?
 		((sl->linkage == DERIVED_TABLE_TYPE) ?
 		 "DERIVED":