MySQL

Database is the core of all application systems, so to ensure the stable, efficient and safe operation of the database is the most important work of all enterprises. Once a database system fails to provide services, it may cause the entire system to

One of the most incredible MySQL deadlock analysis Deadlock problem Background Do MySQL code in-depth analysis also some years, plus their own 10 years or so of database core research and development experience, since the mysql/innodb

It suddenly dawned on me today that 1 of the Int (1) and tinyint (1) in MySQL only specify the display length, not the storage length, only useful if the field specifies Zerofill. The limit of the digits is basically meaningless.Int (5) Here 5

When we use query statements, we often have to return the first few or the middle of a few rows of data, this time what to do? Don't worry,MySQL has provided us with such a feature.SELECT * FROM table LIMIT [offset,] rows | rows offset OffsetThe

1. Optimize your query for query cachingMost MySQL servers have query caching turned on. This is one of the most effective ways to improve sex, and this is handled by the MySQL database engine. When many of the same queries are executed multiple

Docker is an open-source application container engine that allows developers to package theirApplication and dependency packages into a portable container, and then publish to any popularVirtualization can also be implemented on Linux machines.

If the number of records that meet the criteria in Table B is greater than 1, there will be a case of 1:n, so the result after the left join will be more than the number of records in Table A.For example: The structure of member and Member_login_log

Problem starts with using MySQL command to insert Chinese data cannot be plugged inERROR 1366 (HY000): Incorrect string value: ' \xd6\xd0\xce\xc4 ' for column.Start viewing questions about the character set.If you use Set names ' GBK ';or set

Today, after a database migration to a project, there was an error with field ' xxx ' doesn ' t having a default value, and this error was never seen before the migration. Later, after the inquiry manual and other information, found that the error

Premise:1. The Hosts file has been configured and password-free login2. The required Yaml file has been uploaded to the main control sideFirst, using Ansible installation Nginx1. nginx.yaml file1 ---2 -Hosts:clong3 Remote_user:root4 Gather_facts:no5

1. What is a transactionA transaction is a combination of one or more database operation statements with acid,4 characteristics.Atomicity: Either all succeeds or all is undoneIsolation: Transactions are independent from one another and are not

Sometimes for servers with better efficiency, you can restart Apache services on a timed basis. Make the site run faster.Add a scheduled task with the AT command. For the use of syntax can go to window-"Start"-"Run" cmd "-" execute Command "at/", so

MySQL single-instance reset password two waysIn work learning, we sometimes forget the database password, the following is the MySQL single-instance password reset steps.Description(1) [[email protected] ~]# cat/etc/redhat-releaseCentOS Release 6.7 (

Because of the JavaScript language async feature. A callback function is used when you use node. js to run very many operations, including an Access database. Assume that the business logic in the code is slightly more complex, with a callback layer

MySQL, the default is auto-commit, that is , autocommit = 1; But in this case, there are problems in some situations: for example:If you want to insert 1000 data at a time,MySQL will commit1000, If we turn off the autocommit [autocommit = 0],

MySQL Types to Java Types for Resultset.getobject () MySQL Type Name Return value GetColumnClassName of returned as Java Class BIT(1)(New in MySQL-5.0) BIT java.lang.Boolean

MySQL query cache and MySQL Cache MySQL query cache improves the performance of a single node in just a few ways. The cache is the first, because the memory performance is much higher than the disk performance. Cache is also a typical space-for-time

Replication of Mysql-13mysql, replication of Mysql-13mysql 1. mysql replication Concept The DDL and DML operations of the primary database are uploaded to the replication server through binary logs, and these log files are re-executed on the

Mysql server is running with the -- skip-grant-tables option, The MySQL server is running with the -- skip-grant-tables option so it cannot execute this statementIt seems that MYSQL is still running in the -- skip-grant-tables mode. How can I bring

Modify the permission that mysql allows the host to access. mysql allows the host permission. Enable mysql Remote Access PermissionsBy default, mysql users do not have the permission for remote access. Therefore, when the program is not on the same