Nested cast() clause outputs zero length #34901
Description
Bug Report
1. Minimal reproduce step (Required)
First open a mysql client with option --column-type-info, such as mysql --comments --column-type-info --host 127.0.0.1 --port 3306 -u root -p.
Then by executing a statement with nested CAST(), such as select cast(cast(1 as binary) as binary);, it can be found that the length field is wrong.
2. What did you expect to see? (Required)
mysql> select cast(cast(1 as binary) as binary);
Field 1: `cast(cast(1 as binary) as binary)`
Catalog: `def`
Database: ``
Table: ``
Org_table: ``
Type: VAR_STRING
Collation: binary (63)
Length: 2
Max_length: 1
Decimals: 31
Flags: BINARY
+----------------------------------------------------------------------+
| cast(cast(1 as binary) as binary) |
+----------------------------------------------------------------------+
| 0x31 |
+----------------------------------------------------------------------+
1 row in set (0.00 sec)3. What did you see instead (Required)
mysql> select cast(cast(1 as binary) as binary);
Field 1: `cast(cast(1 as binary) as binary)`
Catalog: `def`
Database: ``
Table: ``
Org_table: ``
Type: VAR_STRING
Collation: binary (63)
Length: 0
Max_length: 1
Decimals: 31
Flags: NOT_NULL BINARY
+----------------------------------------------------------------------+
| cast(cast(1 as binary) as binary) |
+----------------------------------------------------------------------+
| 0x31 |
+----------------------------------------------------------------------+
1 row in set (0.00 sec)4. What is your TiDB version? (Required)
| Release Version: v6.1.0-alpha-490-g9d0d45981
Edition: Community
Git Commit Hash: 9d0d459816705e60205d074f3183c8773086e2b0
Git Branch: master
UTC Build Time: 2022-05-23 14:59:53
GoVersion: go1.18.2
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |