Updating value of decimal field results to ERROR 1265 (01000): Data Truncated

[nanne007]

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.

Ref pingcap/tidb-bench#14 。
When doing tpcc on tidb, I came across the same problem as the issue points out.

mysql> desc decimals;
+-------+---------------+------+-----+---------+-------+
| Field | Type          | Null | Key | Default | Extra |
+-------+---------------+------+-----+---------+-------+
| a     | decimal(20,0) | NO   |     | NULL    |       |
+-------+---------------+------+-----+---------+-------+
1 row in set (0.06 sec)

mysql> select * from decimals;
+-----+
| a   |
+-----+
| 201 |
+-----+
1 row in set (0.00 sec)

2. What did you expect to see?

mysql> update decimals set a = a + 1.23;
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> select * from decimals;
+-----+
| a   |
+-----+
| 202 |
+-----+
1 row in set (0.00 sec)

3. What did you see instead?

mysql> update decimals set a = a + 1.23;
ERROR 1265 (01000): Data Truncated
mysql> select * from decimals;
+-----+
| a   |
+-----+
| 201 |
+-----+
1 row in set (0.00 sec)

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?

mysql> select tidb_version();
+----------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                           |
+----------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v1.0.4-1-ga05e014
Git Commit Hash: a05e0146bd7f085938d2631b3726cca7d102537e
Git Branch: release-1.0
UTC Build Time: 2017-12-11 03:07:11 |
+----------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.04 sec)

[shenli]

@lerencao Thanks for your feedback!
@XuHuaiyu PTAL

[coocood]

@lerencao
Thanks for your report.
When a decimal value is truncated by precision, we should return a warning instead of an error.
We will fix it soon.

[ghost]

@coocood I encountered the same problem in v1.0.7.
When will the solution be ready?

[coocood]

@Robert-Xie
In a few days.

[ghost]

ok. Thanks.

[zz-jason]

was fixed by #5801