alter set/enum type column does not check constraint

[xiongjiwei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table if exists t;
create table t(a set('a', 'b', 'c'));
insert into t (a) values ('a'), ('b'), ('c');
alter table t change a a set('a', 'b', 'c', 'c');

2. What did you expect to see? (Required)

[HY000][1291] Column 'a' has duplicated value 'c' in SET

3. What did you see instead (Required)

success

mysql> show create table t;
+-------+------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                           |
+-------+------------------------------------------------------------------------------------------------------------------------+
| t     | CREATE TABLE `t` (
  `a` set('a','b','c','c') DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

4. What is your TiDB version? (Required)

[sre-bot]

Integrity check:
component severity RCA symptom affect_version fix_version fields are empty

Please comment /info to get template

[seiya-annie]

/info

[xiongjiwei]

Please edit this comment to complete the following information

Bug

1. Root Cause Analysis (RCA)

Alter set/enum type column does not check constraint

2. Symptom

alter table t change a a set('a', 'b', 'c', 'c');  #success

3. Minimal steps to reproduce the bug (optional)

drop table if exists t;
create table t(a set('a', 'b', 'c'));
alter table t change a a set('a', 'b', 'c', 'c');

show create table t;
+-------+------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                           |
+-------+------------------------------------------------------------------------------------------------------------------------+
| t     | CREATE TABLE `t` (
  `a` set('a','b','c','c') DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

4. Solution (optional)

• check constraint for enum/set column type
• check type compatible for set type

5. W/A (Workaround)

• No

6. Affected versions

[v3.0.0:v3.0.18],[v4.0.0:v4.0.6]

7. Fixed versions

[v3.0.19], [v4.0.7]

[seiya-annie]

Please edit this comment to complete the following information

Bug

Note: Make Sure that 'component', and 'severity' labels are added
Example for how to fill out the template: #20100

1. Root Cause Analysis (RCA)

Alter set/enum type column does not check constraint

2. Symptom

alter table t change a a set('a', 'b', 'c', 'c'); #success

3. All Trigger Conditions

drop table if exists t;
create table t(a set('a', 'b', 'c'));
alter table t change a a set('a', 'b', 'c', 'c');

show create table t;
+-------+------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+------------------------------------------------------------------------------------------------------------------------+
| t | CREATE TABLE t (
a set('a','b','c','c') DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

4. Workaround (optional)

5. Affected versions

[v3.0.0:v3.0.18],[v4.0.0:v4.0.6]

6. Fixed versions

[v3.0.19], [v4.0.7]