Data cannot be saved

I read the code carefully and rebuilt the data table, but still can't solve this thorny problem? ? Can any mas...

From [MySQLdiscussion group] 2019-12-11 11:47:07 0  2  1168

mysql - select count(1) 统计太慢，怎么优化？

我有一张表400w+数据，单表查询都很慢，当关联时就更慢了。 请问还有什么可以优化的方法吗？ mysql> select count(1) from test; count(1) +----------+ ...

From [MySQLdiscussion group] 2017-04-17 13:35:16 0  1  1168

mysql - How to record table structure changes in the database?

During the development process, the table structure will always need to be changed. Can each change to the tab...

From [MySQLdiscussion group] 2017-06-24 09:41:40 0  1  1167

linux - perl调用mysql时出现的错误——*** glibc detected *** perl: double free or corruption (!prev):

最近更新了一次perl，覆盖了原来系统自带的perl（从10.1到14.4）.更新后重新安装了所需的模块DBI和DBD::msyql，但现在每次用perl调用mysql的时候，SQL语句可以执行成功，但就是会报错。脚本如...

From [MySQLdiscussion group] 2017-04-17 11:16:12 0  2  1167

mysql - For these two SQL statements, one uses or and the other uses union all. The performance should be better than the latter, right?

{code...} This is {code...} for union all

From [MySQLdiscussion group] 2017-05-18 10:56:52 0  2  1166

When the APP is uploaded to the computer server, the problem of incomplete data upload occurs.

I wrote a mobile app. The server is Apache and I used thinphp5.0 to write a server. Now when the mobile phone ...

From [MySQLdiscussion group] 2018-08-19 17:41:18 0  1  1164

phpstudy mysql restarts infinitely. The error log shows the following content

The mysql error of phpstudy v8 is unknown variable 'table_cache=256'. A problem occurred before I started lear...

From [MySQLdiscussion group] 2020-04-30 12:06:37 0  0  1162

The database cannot be inserted, please answer, thank you

<?phprequire 'connect.php';$sql="INSERT INTO 'student'('name','course'...

From [MySQLdiscussion group] 2020-05-17 10:58:29 0  1  1161

mysql cannot start

It was started and terminated. It kept repeating without any prompt. The content cannot be pure English, and t...

From [MySQLdiscussion group] 2019-03-09 09:48:27 0  6  1161

How to design large distributed system reports?

I was really speechless. The second submission was rejected again because "the content belongs to a techn...

From [MySQLdiscussion group] 2017-06-20 10:05:40 0  1  1161

In the php toolbox, if I forget the root password, how to reset the root password?

From [MySQLdiscussion group] 2017-08-28 11:37:01 0  1  1159

mysql - How to solve the problem that two tables refer to each other as foreign keys in a database table

I have two tables, one is the employee table and the other is the department table. The employee table has two...

From [MySQLdiscussion group] 2017-06-08 11:03:31 0  2  1157

trigger - MySQL defines a trigger to return an auto-incrementing ID

Define a trigger in MySQL to return the self-increasing id value. The code is as follows: {code...} An error o...

From [MySQLdiscussion group] 2017-05-27 17:39:10 0  1  1153

How to query the foreign key name in MYSQL

Why can't I get the foreign key name?

From [MySQLdiscussion group] 2018-06-21 17:49:27 0  1  1152

How to retrieve records sorted by or in sql statement

For example, this related article statement: SELECT * FROM zbp_post WHERE log_Type = '0' AND log_Status = '0' ...

From [MySQLdiscussion group] 2020-07-11 12:00:36 0  1  1151