MySQL

First we create a comma-delimited string. CREATE TABLE Test (id int (6) NOT NULL auto_increment,primary KEY (ID), pname varchar (a) not null,pnum varchar (a) NOT null) ; Then insert the test data with a comma-delimited INSERT into Test (pname,pnum)

This article is based on CentOS 64-bit 1. Download MySQL first (mysql-5.6.27-linux-glibc2.5-x86_64.tar.gz) Download http://dev.mysql.com/downloads/from official website Select the appropriate Linux version 2. Copy the

A netizen asked in MySQL How to use only SQL statements to export files with a date format. Feel a little meaning, and then try it. The export file uses select INTO OUTFILE but the value behind OUTFILE cannot use variables, so it can only be

SQL Statement General Order Ghol: group by,having, order By,limit If you are grouping, you should use the sorting of the grouped fields Group by Grammar Limit Start, length Remove Duplicate Records default is All Select Distinct Field from Select

MySQL single-machine multi-instance read-write separation can be achieved through third-party software, one of which is called simple read-write separation software is today brought to everyone's amoeba software.The amoeba software used for this

WhyDisadvantages of traditional replication and Gtids switchingWhen the replication fault occurs, the most headache is the adjustment of the replication architectureOnce master is down, you need to configure a slave as MasterThe binary log file is

0x01MySQL multi-table query and sub-queryJoin query: Two or more tables joined in advance, based on the results of the join queryCross join: Less intersection, equivalent to (a+b) * (c+d+e) of the resulting form with lessNatural Coupling---can only

IndexUse the index to quickly access specific information in the Database tutorials table. An index is a structure that sorts the values of one or more columns in a database table, such as the Last Name (lname) column of an employee table. If you

Appears out of the resources when opening file './xxx. MYD ' (errcode:24) error is because the number of open files exceeds the--open-files-limit of MY.CNF.The OPEN-FILES-LIMIT option cannot be modified directly on the MySQL command line and must be

Xtrabackup backing up the MySQL database1. Installing dependent Packages650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M00/78/78/wKiom1Z9E7DhrU7MAAAnW21ULTQ385.png "title=" 9.png " alt= "Wkiom1z9e7dhru7maaanw21ultq385.png"/>#yum-y Install

The first question first:In principle, the index can be added to any field, but some fields do not need to be indexed, or, instead, add a bad.1, the table's primary key, the foreign key must have the index;2, the data volume of more than 300 of the

Error Description:Add user insert into Mysql.user (Host,user,password) VALUES ("localhost", "Test", Password ("1234"));Report the following error 1364 (HY000): Field ' ssl_cipher ' doesn ' t has a default value errormysql5.1 The above version, I was

MySQL regular backup is an important task, but manual operation is too cumbersome, but also difficult to avoid omissions, use the following method to let the system regularly back up data. Use the system crontab to execute the backup file regularly,

MySQL three major column typesNumeric typeIntegral type: Tinyint1 of bytes 8 Digit bit Storage Range 0---2^8-(0--255)0000 0000 =01111 1111 =2^8-1=255The computer in order to indicate a number is negative, will be the highest bit ( left ) of the 0/1,

Mysql query statement (mysql study note 7 ), SQLStatement General sequence GHOL:Group by, having, order by, limit For grouping, sort the grouping fields.GroupSyntax Limit start, length Remove duplicate recordsDefault Value:All Select

To solve the problem of Chinese garbled characters displayed in the MySQL client output window, Recently, it was found that when querying table data in the MySQL dos client output window, Chinese data in the table is displayed as garbled characters,

An error occurred while installing Mysql, The driver was updated, causing a problem with the wireless Nic. However, even if the driver is downloaded from the official website, it cannot be done well, and it is particularly difficult. However, you

Summary of the Nested-Loop Join algorithm in MySQL, After playing MySQL for more than two years, I found that many people say that MySQL is inferior to Oracle in terms of optimizer. In fact, to some extent, it is true, however, after all, MySQL is

Comparison of implementation labels between REDIS and MYSQLHere we will illustrate the data conversion problem between REDIS and MYSQL. REDIS is a typical KEY-value nosql database and provides an additional rich data type. Here we briefly list the

How to differentiate the use of union and join statements in MySQL, Union and join are related words that are frequently seen when multiple tables need to be joined. I will not talk about the specific concept. I want to know how to query them online,