MySQL

The master-slave replication of the MySQL server is divided into two situations: the MySQL version of the slave server in the replication structure is the same or higher than that of the master server. ######################################## #######

There is a table with relatively large data, and you need to DELETE the association. When you DELETE the table, you will find the following SQL error: DELETE FROM test. test1 a where exists (SELECT 1 FROM test. test2 B WHERE. recordID = B. smsInfoID

MySQL has two types of variables: local variables and Session-level variables: most configuration options of www.2cto.com MySQL have corresponding Session-level or Global-level variables which can be changed in client programs such as mysql, thus

During maintenance, one day a customer sent me a website saying that the connection could not be reached. Then I checked that the database was too high, it is normal to delete some data, but it is also possible to delete some data without

Some developers, especially those who have contact with mysql, may encounter slow mysql queries. Of course, I am referring to a large data volume of millions or tens of millions, not dozens of times, next we will look at the solution to slow query.

MySQL: 1. do not export the statement for table creation, because the table has been created: exported by default, drop table first and then create table; 2. add ignore to the exported insert statement to allow repeated execution: ignore is not

Mysql Stored Procedure variable concatenation sometimes requires fuzzy query, but at the same time we need to use the variable during fuzzy query, we want to splice a % after the variable to match the fuzzy query, then we will use the concat

When mysql is started in linux, the problem of Can't connect to local MySQL server through socket occurs: mysql is started in linux! Can't connect to local MySQL server through socket solution: (my solution is successful! For more information, see!

The auto_increment problem in mysql was found to be a very simple problem during a visit to the Forum, but caused widespread attention: This is a very early interview question:A table contains an ID auto-incrementing primary key. After 17 records

In MySQL, records of pure values can be enclosed by no single quotation marks in the program. If only a number is included in a string type record, no single quotation marks can be added. The records after the as statement are the same as those

Mysql creates a stored procedure and function. A stored procedure is a set of SQL statements that can be stored on the server. You can use create procedure and create function on the client to CREATE a stored PROCEDURE or FUNCTION. CALL the created

Using command line Input net start mysql in win7 to start mysql Database Service has plagued me for a long time. After reading a lot of information, I finally found a solution.It turns out that running mysql does not run the cmd program as an

Migrate the system database from MySQL 5.5 to PostgreSQL 9.1 in Windows Server 2003x64 Simplified Chinese, MySQL 5.5 (UTF8 encoding), PostgreSQL 9.1.4-1 (UTF8 encoding) Spring 3.0.7, struts 2.3.4, Hibernate 3.5.5 migration from MySQL to PostgreSQL *

The usage of Mysql order by has encountered some problems in the process of using order by today. It was found that the previous understanding of order by is incorrect. I saw the order by usage on the w3s website and thought it was to sort the

Errors in mysql master-slave replication and solutions errors in slave logs code 1: [error] ERROR reading packet from server: Client requested master to start replication from impossible position; the last event was read from 'mysql-bin.000016' at 45

How to convert the MYSQL timestamp to the general time format UNIX_TIMESTAMP (date)? If no parameter is called, a Unix timestamp (the number of seconds since '2017-01-01 00:00:00 'GMT) is returned ). If UNIX_TIMESTAMP () is called with a date

Knowledge about SQL operations for MYSQL SET fields [php] 'mark' set ('index', 'best', 'hot ') , there are few people familiar with it. I have been searching for a long time. I finally got a set of knowledge points and looked at the above structure.

MySQL's increase in reading the exceptional Error Buffer (MySQL 5.6) first explains what is an error buffer? In MySQL, the Error Buffer only records the last error. If a new error is generated, the old one will be overwritten. To know what error

Usage of MySQL files log files are located in long_query_time = 2log-slow-queries = log-error = log = C: \ log under the data DIRECTORY by default. the function of the loglog-bin = mysql-bin.index file (binary log index) is to record the absolute

You can use the MySQL command line to change the password of a MySQL database through the MySQL command line. The following describes the MySQL Command Line in detail. If you are interested, take a look. Format: mysqladmin-u username-p old password