MySQL

Mysql lookup statement [SQL] describe table_name; this command is used to display the structure of a table + ---------- + --------- + ------ + ----- + --------- + ------- + | Field | Type | Null | Key | Default | Extra | + ---------- + ----------- +

This article describes how to recover data after Mysql becomes invalid. In some special cases, the Mysql database becomes invalid and the data cannot be exported. 1. reinstall MySQL locally (Installation Directory D: \ Program Files \ MySQL Server 5.

Mysql-e and v simplify code when using mysql-e to generate results to import a specified file: ● to display the statement itself at the same time:-v ● to increase the number of rows of query results: -vv ● to increase the execution time:-vvv can be

What should I do if the restore genie restored mysql? I recently attended practical training courses in the school data center, so I had to frequently communicate with the data center. The recovery wizard installed on the computer room restores my

Mysql table sharding guidelines when using Mysql in large quantities and with high data access, to improve performance, table sharding is required. The following section describes the mysql table sharding standards and will continue to supplement

A bad SQL statement colleague sent an SQL statement, saying that this SQL statement occupies a large amount of server disk space during execution, which is about 10 Gb, and the efficiency is ultra-slow SELECT MIN (order_id ), MAX (order_id) FROM

Advantages of creating and calling stored procedures in My SQL Server Stored Procedures: ① fast execution speed ② templated Program Design ③ reduce network traffic ④ provide system security. what is stored procedure stored Procedure (stored

High-performance MySQL Reading Notes: Find out who holds the lock problem Background: when using MySQL, if the traffic volume is large, there may be a large number of Locked processes, however, it is not easy to identify which SQL is causing the

Mysql statements are case sensitive in linux. In windows, the default SQL statement is lower_case_table_name = 1 (0 is case sensitive and 1 is case insensitive), which is case insensitive. however, in linux, lower_case_table_name = 0 is case

[MySQL] the InnoDB file introduces a notable feature of MySQL: Its pluggable storage engine. Therefore, MySQL files are divided into two types: files related to the MySQL database itself, one is files related to storage engines. This document

[MySQL] Log File overview the log files described here are all files of the MySQL database and have nothing to do with the specific storage engine. The error log of MySQL is similar to alert. log of Oracle. It ends with. err by default. When DBA

Some common O & M records of linux mysql // stop mysql # service mysqld stop // start mysql in safe mode, skip permission check # mysqld_safe -- user = mysql -- skip-grant-tables & // log on to mysql console mysql // modify all root passwords mysql>

The MySQL database table garbled solves the issue of specifying the encoding when creating a mysql database. Many developers use the default encoding, but from my experience, coding databases can avoid garbled characters caused by import and export.

In MySQL, the given time is used to Share a function written yesterday in the nth week of the month. The purpose is to find that the given time is the nth week of the month. [SQL] DELIMITER $ USE't _ girl '$ DROP FUNCTION IF exists' weekofmonth' $

The three locking mechanisms of MySQL database locking mechanism is a rule designed by the database to ensure data consistency and enable the access of various shared resources in an orderly manner during concurrent access. MySQL storage engines use

The mysql backup script writes a mysql backup file today, mainly using the mysqldump tool. The requirement is to back up some databases at three o'clock every day and keep the backups for two days. Simple requirement: The following script #!

Export records from mysql to hdfs 01 ConnectURL = jdbc: mysql: // localhost: 3306/user_action0203UserName = root0405PassWord = 1234560607 OutputPath =/hdfs/recommend/user_action/login = watch_record1011Columns = id, uid, mid, handler = 'sqoop job

To modify the character set, use the mysql command. Mysql> SET character_set_client = utf8; mysql> SET character_set_connection = utf8; Use mysql> show variables like 'character % '; view, we found that the database encoding has been changed to utf8

On a single machine, install and run two mysql database instances to facilitate testing and use two mysql database instances. Taking windows as an example, of course, installing the first mysql database is quite simple. But you need to install it

Mysql basics: log on and exit, change the user password, add or delete users, learn mysql at the beginning of today, first contact user management, share with you the bet: mysql commands can be case sensitive ============ Logon and exit =============