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SET @@session.default_storage_engine = 'MyISAM';
create table t1 (a int not null,
b int as (-a),
c int as (-a) persistent);
insert into t1 (a) values (1), (1), (2), (2), (3);
create view v1 (d,e) as select abs(b), abs(c) from t1;
select d,e from v1;
d e
1 1
1 1
2 2
2 2
3 3
select is_updatable from information_schema.views where table_name='v1';
is_updatable
NO
explain extended select d,e from v1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 5 100.00
Warnings:
Note 1003 select abs(`test`.`t1`.`b`) AS `d`,abs(`test`.`t1`.`c`) AS `e` from `test`.`t1`
create algorithm=temptable view v2 (d,e) as select abs(b), abs(c) from t1;
show create view v2;
View Create View character_set_client collation_connection
v2 CREATE ALGORITHM=TEMPTABLE DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v2` AS select abs(`t1`.`b`) AS `d`,abs(`t1`.`c`) AS `e` from `t1` latin1 latin1_swedish_ci
select d,e from v2;
d e
1 1
1 1
2 2
2 2
3 3
explain extended select d,e from v2;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 5 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00
Warnings:
Note 1003 /* select#1 */ select `v2`.`d` AS `d`,`v2`.`e` AS `e` from `test`.`v2`
create view v3 (d,e) as select d*2, e*2 from v1;
select * from v3;
d e
2 2
2 2
4 4
4 4
6 6
explain extended select * from v3;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 5 100.00
Warnings:
Note 1003 select abs(`test`.`t1`.`b`) * 2 AS `d`,abs(`test`.`t1`.`c`) * 2 AS `e` from `test`.`t1`
drop view v1,v2,v3;
drop table t1;
create table t1 (a int not null,
b int as (-a),
c int as (-a) persistent);
insert into t1 (a) values (1), (2), (3), (1), (2), (3);
create view v1 as select distinct b from t1;
select * from v1;
b
-1
-2
-3
explain select * from v1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6
2 DERIVED t1 ALL NULL NULL NULL NULL 6 Using temporary
select * from t1;
a b c
1 -1 -1
2 -2 -2
3 -3 -3
1 -1 -1
2 -2 -2
3 -3 -3
drop view v1;
create view v1 as select distinct c from t1;
select * from v1;
c
-1
-2
-3
explain select * from v1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6
2 DERIVED t1 ALL NULL NULL NULL NULL 6 Using temporary
select * from t1;
a b c
1 -1 -1
2 -2 -2
3 -3 -3
1 -1 -1
2 -2 -2
3 -3 -3
drop view v1;
drop table t1;
create table t1 (a int not null,
b int as (-a),
c int as (-a) persistent);
insert into t1 (a) values (1), (2), (3), (4);
create view v1 as select b+1 from t1 order by 1 desc limit 2;
select * from v1;
b+1
0
-1
MariaDB-5.3: the following EXPLAIN produces incorrect #rows for table t1.
MariaDB-5.3: this is expected to go away when FROM subquery optimizations are pushed
explain select * from v1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
2 DERIVED t1 ALL NULL NULL NULL NULL 4 Using filesort
drop view v1;
create view v1 as select c+1 from t1 order by 1 desc limit 2;
select * from v1;
c+1
0
-1
MariaDB-5.3: the following EXPLAIN produces incorrect #rows for table t1.
MariaDB-5.3: this is expected to go away when FROM subquery optimizations are pushed
explain select * from v1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
2 DERIVED t1 ALL NULL NULL NULL NULL 4 Using filesort
drop view v1;
drop table t1;
create table t1 (a int,
b int,
c int as (-a),
d int as (-a) persistent,
primary key(a));
insert into t1 (a,b) values (10,2), (20,3), (30,4), (40,5), (50,10);
create view v1 (a,e,f,g) as select a, b+1,c+1,d+1 from t1;
update v1 set a=a+e;
select * from v1;
a e f g
13 3 -12 -12
24 4 -23 -23
35 5 -34 -34
46 6 -45 -45
61 11 -60 -60
select * from t1;
a b c d
13 2 -13 -13
24 3 -24 -24
35 4 -35 -35
46 5 -46 -46
61 10 -61 -61
delete from v1;
select * from v1;
a e f g
select * from t1;
a b c d
insert into v1 (a,e) values (60,15);
ERROR HY000: The target table v1 of the INSERT is not insertable-into
drop table t1;
drop view v1;
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='outer_join_with_cache=off';
create table t1 (a int,
b int as (-a),
c int as (-a) persistent,
primary key(a));
insert into t1 (a) values (1), (2), (3);
create view v1 (x,y,z) as select a,b,c from t1 where b < -1;
select t1.a, v1.x, v1.y, v1.z from t1 left join v1 on (t1.b= v1.y);
a x y z
1 NULL NULL NULL
2 2 -2 -2
3 3 -3 -3
drop view v1;
create view v1 (x,y,z) as select a,b,c from t1 where c < -1;
select t1.a, v1.x, v1.y, v1.z from t1 left join v1 on (t1.c= v1.z);
a x y z
1 NULL NULL NULL
2 2 -2 -2
3 3 -3 -3
drop view v1;
drop table t1;
SET optimizer_switch=@save_optimizer_switch;
create table t1 (a1 int,
b1 int as (-a1),
c1 int as (-a1) persistent);
create table t2 (a2 int,
b2 int as (-a2),
c2 int as (-a2) persistent);
insert into t1 (a1) values (1), (2);
insert into t2 (a2) values (2), (3);
create view v1 as select * from t1,t2 union all select * from t1,t2;
select * from v1;
a1 b1 c1 a2 b2 c2
1 -1 -1 2 -2 -2
2 -2 -2 2 -2 -2
1 -1 -1 3 -3 -3
2 -2 -2 3 -3 -3
1 -1 -1 2 -2 -2
2 -2 -2 2 -2 -2
1 -1 -1 3 -3 -3
2 -2 -2 3 -3 -3
drop view v1;
drop table t1, t2;
create table t1 (a int,
b int as (-a),
c int as (-a) persistent);
create table t2 like t1;
create view v1 as select a,b,c from t1;
create view v2 as select a,b,c from t2 where b in (select b from v1);
show create view v2;
View Create View character_set_client collation_connection
v2 CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v2` AS select `t2`.`a` AS `a`,`t2`.`b` AS `b`,`t2`.`c` AS `c` from `t2` where `t2`.`b` in (select `v1`.`b` from `v1`) latin1 latin1_swedish_ci
drop view v2, v1;
drop table t1, t2;
create table t1 (a int,
b int as (-a),
c int as (-a) persistent);
insert into t1 (a) values (1),(1),(2),(2),(3),(3);
create view v1 as select b from t1;
select distinct b from v1;
b
-1
-2
-3
select distinct b from v1 limit 2;
b
-1
-2
select distinct b from t1 limit 2;
b
-1
-2
prepare stmt1 from "select distinct b from v1 limit 2";
execute stmt1;
b
-1
-2
execute stmt1;
b
-1
-2
deallocate prepare stmt1;
drop view v1;
create view v1 as select c from t1;
select distinct c from v1;
c
-1
-2
-3
select distinct c from v1 limit 2;
c
-1
-2
select distinct c from t1 limit 2;
c
-1
-2
prepare stmt1 from "select distinct c from v1 limit 2";
execute stmt1;
c
-1
-2
execute stmt1;
c
-1
-2
deallocate prepare stmt1;
drop view v1;
drop table t1;
create table t1 (a int,
b int as (-a),
c int as (-a) persistent);
create view v1 as select * from t1 where b > -2 && c >-2 with check option;
insert into v1 (a) values (1);
insert into v1 (a) values (3);
ERROR 44000: CHECK OPTION failed `test`.`v1`
insert ignore into v1 (a) values (2),(3),(0);
Warnings:
Warning 1369 CHECK OPTION failed `test`.`v1`
Warning 1369 CHECK OPTION failed `test`.`v1`
select * from t1;
a b c
1 -1 -1
0 0 0
drop view v1;
drop table t1;
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