Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
mysql> create table t(i int);
Query OK, 0 rows affected (0.10 sec)
mysql> insert into t values(1);
Query OK, 1 row affected (0.02 sec)
mysql> alter table t add column b bit(1) default b'0';
Query OK, 0 rows affected (0.28 sec)
mysql> select b from t;
+------------+
| b |
+------------+
| 0x00 |
+------------+
1 row in set (0.00 sec)
mysql> alter table t modify column b bit(1) default b'1';
Query OK, 0 rows affected (0.09 sec)
mysql> select b from t;
+------------+
| b |
+------------+
| 0x01 |
+------------+
1 row in set (0.01 sec)
2. What did you expect to see? (Required)
Second select should see 0x00 still.
3. What did you see instead (Required)
Second select outputs 0x01.
4. Affected version (Required)
v3.0.0, v3.1.0, v4.0.0
5. Root Cause Analysis
Filling default value for missing bit column of rows doesn't regard origin default value.
Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
2. What did you expect to see? (Required)
Second select should see 0x00 still.
3. What did you see instead (Required)
Second select outputs 0x01.
4. Affected version (Required)
v3.0.0, v3.1.0, v4.0.0
5. Root Cause Analysis
Filling default value for missing bit column of rows doesn't regard origin default value.