In information schema column table ORDINAL_POSITION is different

[Alkaagr81]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE TABLE t1 (col1 INT, INDEX ((col1 + col1)));

SELECT COLUMN_NAME, ORDINAL_POSITION FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = "t1";

ALTER TABLE t1 ADD COLUMN col2 INT;

SELECT COLUMN_NAME, ORDINAL_POSITION FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = "t1";

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

mysql> CREATE TABLE t1 (col1 INT, INDEX ((col1 + col1)));
Query OK, 0 rows affected (0.01 sec)

mysql> 
mysql> SELECT COLUMN_NAME, ORDINAL_POSITION FROM INFORMATION_SCHEMA.COLUMNS
    -> WHERE TABLE_NAME = "t1";
+-------------+------------------+
| COLUMN_NAME | ORDINAL_POSITION |
+-------------+------------------+
| col1        |                1 |
+-------------+------------------+
1 row in set (0.01 sec)

mysql> 
mysql> ALTER TABLE t1 ADD COLUMN col2 INT;
Query OK, 0 rows affected (0.00 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> 
mysql> SELECT COLUMN_NAME, ORDINAL_POSITION FROM INFORMATION_SCHEMA.COLUMNS
    -> WHERE TABLE_NAME = "t1";
+-------------+------------------+
| COLUMN_NAME | ORDINAL_POSITION |
+-------------+------------------+
| col1        |                1 |
| col2        |                2 |
+-------------+------------------+
2 rows in set (0.00 sec)

3. What did you see instead (Required)

mysql> CREATE TABLE t1 (col1 INT, INDEX ((col1 + col1)));
Query OK, 0 rows affected (0.01 sec)

mysql> 
mysql> SELECT COLUMN_NAME, ORDINAL_POSITION FROM INFORMATION_SCHEMA.COLUMNS
    ->   WHERE TABLE_NAME = "t1";
+-------------+------------------+
| COLUMN_NAME | ORDINAL_POSITION |
+-------------+------------------+
| col1        |                1 |
+-------------+------------------+
1 row in set (0.02 sec)

mysql> 
mysql> ALTER TABLE t1 ADD COLUMN col2 INT;
Query OK, 0 rows affected (0.01 sec)

mysql> 
mysql> SELECT COLUMN_NAME, ORDINAL_POSITION FROM INFORMATION_SCHEMA.COLUMNS
    ->   WHERE TABLE_NAME = "t1";
+-------------+------------------+
| COLUMN_NAME | ORDINAL_POSITION |
+-------------+------------------+
| col1        |                1 |
| col2        |                3 |
+-------------+------------------+
2 rows in set (0.02 sec)

4. What is your TiDB version? (Required)

| Release Version: v5.4.0-alpha-184-g51f53f337-dirty
Edition: Community
Git Commit Hash: 51f53f3376bd548b302f654d6c11096f89119145
Git Branch: master
UTC Build Time: 2021-11-23 02:51:51
GoVersion: go1.16.9
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |

[yudongusa]

@bb7133 assign this to you first.