MySQL Bugs: #105351: Data insertion exception in version 8.0.27

Bug #105351	Data insertion exception in version 8.0.27
Submitted:	28 Oct 2021 2:10	Modified:	19 Nov 2021 19:32
Reporter:	tuantuan Xue	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: DML	Severity:	S2 (Serious)
Version:	8.0.27	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	regression

Description:
We found a serious problem. When inserting with insert select statement, there are data exceptions

How to repeat:
CREATE TABLE test(ID INT,FIELDNAME VARCHAR(100));
INSERT INTO test VALUES(1,'36245');

The result of the query is displayed：

SELECT 
  MAX(id)+1 ,
  '27141' id2
FROM
  test a 
  GROUP BY id2 ;

----------------------------------------
MAX(id)+1  id2     
---------  --------
        2  27141   

However, if you insert this result into the test table：
INSERT INTO test 
SELECT 
  MAX(id)+1 ,
  '27141' id2
FROM
  test a 
  GROUP BY id2 ;

select * from test;

    ID  FIELDNAME  
------  -----------
     1  36245      
(NULL)  27141      

The ID of the data inserted above turned out to be null

Suggested fix:
We changed the way we wrote the sentence, but it was correct：

INSERT INTO test 
SELECT 
  MAX(id+1),
  '27141' id2
FROM
  test a 
  GROUP BY id2

Hello tuantuan Xue,

Thank you for the report and test case.
Observed that 8.0.27 build is affected.

regards,
Umesh

- 8.0.27 - affected

 bin/mysql -uroot -S /tmp/mysql_ushastry.sock
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 8.0.27 MySQL Community Server - GPL

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> create database test;
Query OK, 1 row affected (0.01 sec)

mysql> use test
Database changed
mysql> CREATE TABLE test(ID INT,FIELDNAME VARCHAR(100));
Query OK, 0 rows affected (0.02 sec)

mysql> INSERT INTO test VALUES(1,'36245');
Query OK, 1 row affected (0.01 sec)

mysql> SELECT
    ->   MAX(id)+1 ,
    ->   '27141' id2
    -> FROM
    ->   test a
    ->   GROUP BY id2 ;
+-----------+-------+
| MAX(id)+1 | id2   |
+-----------+-------+
|         2 | 27141 |
+-----------+-------+
1 row in set (0.00 sec)

mysql> INSERT INTO test
    -> SELECT
    ->   MAX(id)+1 ,
    ->   '27141' id2
    -> FROM
    ->   test a
    ->   GROUP BY id2 ;
Query OK, 1 row affected (0.00 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> select * from test;
+------+-----------+
| ID   | FIELDNAME |
+------+-----------+
|    1 | 36245     |
| NULL | 27141     |
+------+-----------+
2 rows in set (0.00 sec)

mysql> shutdown;
Query OK, 0 rows affected (0.00 sec)

This seems to be regression, lowest checked version 8.0.11 not affected

 bin/mysql -uroot -S /tmp/mysql_ushastry.sock
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 8.0.11 MySQL Community Server - GPL

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> create database test;
Query OK, 1 row affected (0.05 sec)

mysql> use test
Database changed
mysql> CREATE TABLE test(ID INT,FIELDNAME VARCHAR(100));
Query OK, 0 rows affected (0.06 sec)

mysql> INSERT INTO test VALUES(1,'36245');
Query OK, 1 row affected (0.09 sec)

mysql> SELECT
    ->   MAX(id)+1 ,
    ->   '27141' id2
    -> FROM
    ->   test a
    ->   GROUP BY id2 ;
+-----------+-------+
| MAX(id)+1 | id2   |
+-----------+-------+
|         2 | 27141 |
+-----------+-------+
1 row in set (0.00 sec)

mysql> INSERT INTO test
    -> SELECT
    ->   MAX(id)+1 ,
    ->   '27141' id2
    -> FROM
    ->   test a
    ->   GROUP BY id2 ;
Query OK, 1 row affected (0.06 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> select * from test;
+------+-----------+
| ID   | FIELDNAME |
+------+-----------+
|    1 | 36245     |
|    2 | 27141     |
+------+-----------+
2 rows in set (0.00 sec)

mysql>

- 5.7.36 not affected

Posted by developer:
 
Fixed as of the upcoming MySQL 8.0.28 release, and here's the proposed changelog entry from the documentation team:

If a query with the sql_buffer_result system variable enabled returned
just one row, and an attempt was made to insert the result into a table,
then an error in setting the output from the temporary table could produce
a data exception.

Thank you for the bug report.

Bug#106193 insert into select,coalesce(sum(),0) not work correct

was marked as a duplicate.