Import into xxx from select xxx group by a with thread=x will report syntax error

[Defined2014]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t(a int);
insert into t values (1);
create table t1(a int);
import into t1 from select sum(a) from t group by a with thread=1; -- syntax error
import into t1 from select sum(a) from t group by a with rollup with thread=1; -- no error

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

no error

3. What did you see instead (Required)

report error

4. What is your TiDB version? (Required)

mysql> select tidb_version();
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                           |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v8.5.0-alpha-296-g8c888234ff
Edition: Community
Git Commit Hash: 8c888234ff2a6c606593db3d1ebc929f0cd7f876
Git Branch: master
UTC Build Time: 2024-12-09 02:23:26
GoVersion: go1.23.4
Race Enabled: false
Check Table Before Drop: false
Store: unistore |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

A workaround way, create a view to instead of directly use group by sql.

[D3Hunter]

import into t1 from select sum(a) from t group by a with thread=1; -- syntax error

yes, with import-options might conflict with with rollup, you can wrap the query inside parenthesis, like

mysql> import into t1 from (select sum(a) from t group by a) with thread=1;
Query OK, 0 rows affected (0.18 sec)
Records: 0, ID: 17c6e44c-26f2-43cc-ae14-89c8dc83389b

[D3Hunter]

it's not a bug, will update doc about this behavior later

[lance6716]

pingcap/docs-cn#19261