create unique index without partition column error when enable-global-index is true

[crazycs520]

Development Task

Please answer these questions before submitting your issue. Thanks!

related issue: #18032

1. Minimal reproduce step (Required)

TiDB config:

enable-global-index=true

create table t (a int, b int, unique index idx(a)) partition by list columns(b) (partition p0 values in (1), partition p1 values in (2));

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

Execute success.

Currently, create table without unique index, but alter table add unique index later will be success.

test> create table t (a int, b int) partition by list columns(b) (partition p0 values in (1), partition p1 values in (2));
Query OK, 0 rows affected
Time: 0.098s
test> alter table t add unique index idx (a);
Query OK, 0 rows affected
Time: 2.818s

3. What did you see instead (Required)

test> create table t (a int, b int, unique index idx(a)) partition by list columns(b) (partition p0 values in (1), partition p1 values in (2));
(1503, "A UNIQUE INDEX must include all columns in the table's partitioning function")

4. What is your TiDB version? (Required)

> select tidb_version();
+-------------------------------------------------------------------+
| tidb_version()                                                    |
+-------------------------------------------------------------------+
| Release Version: v4.0.0-beta.2-1812-gd33b81b1e                    |
| Edition: Community                                                |
| Git Commit Hash: d33b81b1ee69bd60a56e45f87774e76014720a6e         |
| Git Branch: master                                                |
| UTC Build Time: 2020-12-14 12:59:19                               |
| GoVersion: go1.14.4                                               |
| Race Enabled: false                                               |
| TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306 |
| Check Table Before Drop: false                                    |
+-------------------------------------------------------------------+

[crazycs520]

@tiancaiamao PTAL