pingcap/tidb

DDL RowsAffected is not correct?

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#12,705 建立於 2019年10月15日

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challenge-programgood first issuehelp wantedsig/sql-infratype/compatibility

描述

Description

Bug Report

TiDB Always return 0 Rows Affected in DDL.

  1. What did you do? If possible, provide a recipe for reproducing the error.
create database rrrr;
use rrrr;
create table r (i int);
drop database rrrr;
  1. What did you expect to see?

In Mysql 8.0.16

mysql> create database rrrr;
Query OK, 1 row affected (0.03 sec)

mysql> use rrrr;
Database changed
mysql> create table r (i int);
Query OK, 0 rows affected (0.06 sec)

mysql> drop database rrrr;
Query OK, 1 row affected (0.04 sec)
  1. What did you see instead?

In TiDB

mysql> create database rrrr;
Query OK, 0 rows affected (0.18 sec)

mysql> use rrrr;
Database changed
mysql> create table r (i int);
Query OK, 0 rows affected (0.18 sec)

mysql> drop database rrrr;
Query OK, 0 rows affected (0.36 sec)
  1. 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: v3.0.4-17-g0607ada6ca
Git Commit Hash: 0607ada6cab0bf72a82aaf754813fbbb423115ee
Git Branch: HEAD
UTC Build Time: 2019-10-12 06:34:41
GoVersion: go version go1.13 linux/amd64
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

SIG slack channel

#sig-exec

Score

  • 900

Mentor

  • @lzmhhh123

貢獻者指南

技術棧
gosql
領域
database
議題類型
bug
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
half day
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
stale
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
Go programming languageSQLTiDB architecture
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
50
研究方向
Investigate how TiDB reports rows affected for DDL statements like CREATE DATABASE and DROP DATABASE. Compare with MySQL's behavior as described. The issue likely lies in the executor or session handler where the affected rows count is set. Consider looking at the DDL execution code in the `executor` package and the MySQL protocol response construction. The mentor @lzmhhh123 can provide guidance.
DDL RowsAffected is not correct? · pingcap/tidb#12705 | Good First Issue