MySQL

Mysql basics: mysql column type-string-CHAR, which is a synonym for CHAR (1. · [NATIONAL] VARCHAR (M) [BINARY] variable-length string. M indicates the maximum column length. M ranges from 0 to 65,535. (The maximum actual length of a VARCHAR is

Mysql has a one-to-multiple relationship. Multiple items are combined to display all the content (group_concat () method and group by). mysql has a one-to-multiple relationship, combine multiple items into one and display all the content

When MySQL uses the select distinct name from table Statement of MYSQL to deduplicate a specified field, only the information of the name field after deduplication is output, the hope is to output the information about the examinee's ID, examination

Mysql import csv file mysql load data infile command can import the DATA in the csv flat file to the database. In linux: Load data infile '/home/test/dump/ip_location.csv 'into TABLE ip_location character set utf8 fields terminated by', 'enabledby'

MySQL learning footprint record 07 -- Data Filtering -- use regular expressions to retrieve the search data used in this article mysql> SELECT prod_name FROM products -> ORDER BY prod_name;+----------------+| prod_name |+--------

For MySQL DML operations, we recommend that you (I) INSERT large data volumes (I) replace a single row with multiple rows: insert into t values (),(),(),...  (2) LOAD DATA INFILE ... INTO TABLE t  (3) Write a temporary table and INSERT... SELECT (4)

MySQL query solution: Mysql calculates the values of multiple fields. The original database is as follows. All fields are of the int type. +----+---------+---------+| id | column1 | column2 |+----+---------+---------+| 1 | 1 | 2 || 2 |

How to obtain all columns of the mysql database SELECT COLUMN_NAME FROM 'information _ scheme'. 'columns 'where 'table _ name' = 'appstats' order by COLUMN_NAME  Retrieve all fields: SELECT COLUMN_NAME FROM 'information _ scheme'. 'columns 'where

Virtual Machine environment install ubuntu under the mysql-cluster7.3.2 (Single Point server) Deployment environment: System: ubuntu-12.04.2 LTS-server-i386.iso Cluster: mysql-cluster-gpl-7.3.2-linux-glibc23-i686.tar.gz Description: 1, it is best

Mysql data recovery function notes many children's shoes have used the mysqldump and source functions when backing up and restoring the database. However, I feel that the operation is rather inconvenient. I cannot see all operations on the database

For MySQL Data File ibdata1 slimming MySQL after running for a period of time, ibdata1 files will increase the size, even if the table data is deleted, the ibdata1 volume will not decrease. Due to limited hard disk space, the disk space continues to

Mysql master-Slave problem handling records Slave server downtime, resulting in the slave server startup after the show Slave status \ G prompt error Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'binlog

[SQL] MySQL uses mysqldump for full backup and recovery [Objective] Use mysqldump for full backup. It is recommended to enable two Terminal functions in combination with the binlog function provided by mysql for Incremental backup, one Mysql-related

The mysql group by statement can be used to deduplicate a column. Directly run the following statement: Select io_dev_id from io_info where (TID = 1 AND host_name = 'ang1') group by 1;  Deduplicate query by io_dev_id. P: The difference between

The MYSQL service cannot be started, and the message 1067 solution has to vomit that the mysql version is too unstable. After restarting the MYSQL service, it will crash. Baidu has a lot of blogs and can modify my. ini files. Nima doesn't work.

MySQL review notes II 1. Set the password for the root administrator account. Generally, the default password for MySQL is null. If you have not set the root password before, use the mysqladmin command, you can use the following mysqladmin command

I installed mysql in linux6.2 for one day. I didn't expect it to take so long and it is related to my poor foundation. Now let's talk about the installation process. First, let's talk about the environment: rhel6.2 mysql5.1 in linux, a mysql-lib may

Step 1: Change the address of the mysql data storage to the default path/var/lib/mysql/, and change it to/data/mysql/data. mysql> show variables like '%dir%';+-----------------------------------------+----------------------------+| Variable_name

Mysql startup failure error 1067 after Mysql is installed, restart the computer and find that the service cannot be started for the second time. The prompt is as follows: ---------------------- the MySQL service cannot be started. System error.

Shell preliminary: mysql regularly resends local data every day and replaces remote database data 01mysql regularly resends local data every day, to replace the remote database data 02, You need to import the tb_a table in the ser_a database on 192.1