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SET @@session.default_storage_engine = 'MyISAM';
# Case 1. All non-stored columns.
create table t1 (a int generated always as (2+3) virtual);
insert into t1 values (default);
select * from t1;
a
5
insert into t1 values (default);
select * from t1;
a
5
5
drop table t1;
# Case 2. CREATE
# - Column1: "real"
# - Column 2: virtual non-stored
create table t1 (a int, b int generated always as (-a) virtual);
insert into t1 values (1,default);
select * from t1;
a b
1 -1
insert into t1 values (2,default);
select * from t1 order by a;
a b
1 -1
2 -2
drop table t1;
# Case 3. CREATE
# - Column1: "real"
# - Column 2: virtual stored
create table t1 (a int, b int generated always as (-a) stored);
insert into t1 values (1,default);
select * from t1;
a b
1 -1
insert into t1 values (2,default);
select * from t1 order by a;
a b
1 -1
2 -2
drop table t1;
# Case 4. CREATE
# - Column1: virtual non-stored
# - Column2: "real"
create table t1 (a int generated always as (-b) virtual, b int);
insert into t1 values (default,1);
select * from t1;
a b
-1 1
insert into t1 values (default,2);
select * from t1 order by a;
a b
-2 2
-1 1
drop table t1;
# Case 5. CREATE
# - Column1: virtual stored
# - Column2: "real"
create table t1 (a int generated always as (-b) stored, b int);
insert into t1 values (default,1);
select * from t1;
a b
-1 1
insert into t1 values (default,2);
select * from t1 order by a;
a b
-2 2
-1 1
drop table t1;
# Case 6. CREATE
# - Column1: "real"
# - Column2: virtual non-stored
# - Column3: virtual stored
create table t1 (a int, b int generated always as (-a), c int generated always as (-a) stored);
insert into t1 values (1,default,default);
select * from t1;
a b c
1 -1 -1
insert into t1 values (2,default,default);
select * from t1 order by a;
a b c
1 -1 -1
2 -2 -2
drop table t1;
# Case 7. ALTER. Modify virtual stored -> virtual non-stored
create table t1 (a int, b int generated always as (a % 2) stored);
alter table t1 modify b int generated always as (a % 2) virtual;
ERROR HY000: This is not yet supported for generated columns
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`b` int(11) GENERATED ALWAYS AS (`a` MOD 2) STORED
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
# Case 8. ALTER. Modify virtual non-stored -> virtual stored
create table t1 (a int, b int generated always as (a % 2) virtual);
alter table t1 modify b int generated always as (a % 2) stored;
ERROR HY000: This is not yet supported for generated columns
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`b` int(11) GENERATED ALWAYS AS (`a` MOD 2) VIRTUAL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
# Case 9. CREATE LIKE
# - Column1: "real"
# - Column2: virtual non-stored
# - Column3: virtual stored
create table t1 (a int, b int generated always as (-a), c int generated always as (-a) stored);
create table t2 like t1;
insert into t2 values (1,default,default);
select * from t2;
a b c
1 -1 -1
insert into t2 values (2,default,default);
select * from t2 order by a;
a b c
1 -1 -1
2 -2 -2
drop table t2;
drop table t1;
# Case 10. ALTER. Dropping a virtual non-stored column.
# - Column1: virtual non-stored
# - Column2: "real"
create table t1 (a int generated always as (-b) virtual, b int, c varchar(5));
insert into t1 values (default,1,'v1');
insert into t1 values (default,2,'v2');
select * from t1 order by b;
a b c
-1 1 v1
-2 2 v2
alter table t1 drop column a;
select * from t1 order by b;
b c
1 v1
2 v2
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`b` int(11) DEFAULT NULL,
`c` varchar(5) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
# Case 11. ALTER. Dropping a virtual stored column.
# - Column1: virtual stored
# - Column2: "real"
create table t1 (a int generated always as (-b) stored, b int, c char(5));
insert into t1 values (default,1,'v1');
insert into t1 values (default,2,'v2');
select * from t1 order by b;
a b c
-1 1 v1
-2 2 v2
alter table t1 drop column a;
select * from t1 order by b;
b c
1 v1
2 v2
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`b` int(11) DEFAULT NULL,
`c` char(5) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
# Case 12. ALTER. Adding a new virtual non-stored column.
create table t1 (a int, b datetime);
insert into t1 values (1,'2008-09-04');
insert into t1 values (2,'2008-09-05');
select * from t1 order by a;
a b
1 2008-09-04 00:00:00
2 2008-09-05 00:00:00
alter table t1 add column c int generated always as (dayofyear(b)) virtual after a;
select * from t1 order by a;
a c b
1 248 2008-09-04 00:00:00
2 249 2008-09-05 00:00:00
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`c` int(11) GENERATED ALWAYS AS (dayofyear(`b`)) VIRTUAL,
`b` datetime DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
# Case 13. ALTER. Adding a new virtual stored column.
create table t1 (a int, b datetime);
insert into t1 values (1,'2008-09-04');
insert into t1 values (2,'2008-09-05');
select * from t1 order by a;
a b
1 2008-09-04 00:00:00
2 2008-09-05 00:00:00
alter table t1 add column c int generated always as (dayofyear(b)) stored after a;
select * from t1 order by a;
a c b
1 248 2008-09-04 00:00:00
2 249 2008-09-05 00:00:00
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`c` int(11) GENERATED ALWAYS AS (dayofyear(`b`)) STORED,
`b` datetime DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
# Case 15. ALTER. Changing the expression of a virtual non-stored column.
create table t1 (a int, b datetime, c int generated always as (week(b)) virtual);
insert into t1 values (1,'2008-09-04',default);
insert into t1 values (2,'2008-09-05',default);
select * from t1 order by a;
a b c
1 2008-09-04 00:00:00 35
2 2008-09-05 00:00:00 35
alter table t1 change column c c int generated always as (week(b,1)) virtual;
select * from t1 order by a;
a b c
1 2008-09-04 00:00:00 36
2 2008-09-05 00:00:00 36
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`b` datetime DEFAULT NULL,
`c` int(11) GENERATED ALWAYS AS (week(`b`,1)) VIRTUAL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
DROP VIEW IF EXISTS v1,v2;
DROP TABLE IF EXISTS t1,t2,t3;
DROP PROCEDURE IF EXISTS p1;
DROP FUNCTION IF EXISTS f1;
DROP TRIGGER IF EXISTS trg1;
DROP TRIGGER IF EXISTS trg2;
set sql_warnings = 0;
|
