MySQL

1. Use the insert ignore into statement to re-Mysql> INSERTIGNORE intoperson_tbl (last_name, first_name) - VALUES('J','T'); Query OK,1Row affected (0.00sec) MySQL> INSERTIGNORE intoperson_tbl (last_name, first_name) - VALUES('J','T'); Query OK,0Rows

1.MySQL need to redeploy, delete which two files and what commands to executeDelete Arch and data directories2.MySQL Create a DB, create a user to this DB has all permissions, password 123456, only allow 198.168.137.110 machine to access the

1, configure the MySQL client, create a user to get MySQL data, use the MySQL account password to log into the database, > grant all on *.* to [email protected]‘localhost‘ identified by ‘123456789‘;I am testing the environment with all for

MySQL database modify character set, introduce the method of modification1) System Tools Iconv#file filename#mysqldump--default-character-set=utf8 >20180523xxx.sql#file 20180523xxx.sql#iconv-t utf8mb4-c 20180523xxx.sql>20180523xxxutf8mb4.sql#file 20

Get MirrorDocker pull MySQLTo start the container:Docker run-p 3306:3306--name pf-mysql-v/usr/pf/docker/volumn/mysql_conf/my.cnf:/etc/mysql/my.cnf-v/USR/PF /docker/volumn/logs/mysql:/logs-v/usr/pf/docker/volumn/db/mysql:/mysql_data-e

DROP FUNCTION IF EXISTS querychildorglist;CREATE FUNCTION querychildorglist (id VARCHAR (20))RETURNS VARCHAR (2000)BEGINDECLARE stemp VARCHAR (+) DEFAULT ';DECLARE displayids VARCHAR (+) DEFAULT ';DECLARE currparentids VARCHAR (+) DEFAULT ';SET

First, the problem analysisSometimes using the database Remote Connection tool when connecting to MySQL is always not connected, confirmed that the account password is correct, port Telnet port is also a pass.Navicat Premium error is as follows:1130-

Online a lot of posts feel older, and stereotyped. I went to MySQL to see the official online python-driven operation, and found that most of the site is not the same.The drivers that are installed first are:pip install mysql-connector-pythonThe

Utf-8 time-varying length encoding, storing a code point requires 1~4 bytes.However, MySQL UTF8 only stores a maximum of 3 bytes per code point.Therefore, the UTF8 character set cannot store all Unicode code points.Only from 0x000 to 0xFFFF (called

I. MOF's right to withdrawThe Windows Management specification provides the following three ways to compile a managed Object Format (MOF) file into the WMI repository:1. Run MOF file specified as command line argument Mofcomp.exe file.2, using

Tag: Now ()--Current time int select extra format MySQL date form1 --query data for the whole day yesterday2 SELECTDate_format (Date_sub (now (), INTERVAL1 Day) ,'%y-%m-%d 00:00:00') as 'Yesterday start time', Date_format (Date_sub (now (),

Types of characters supported by MySQL: type size Use CHAR 0-255 bytes Fixed length string VARCHAR 0-65535 bytes Variable length string Tinyblob 0-255

server1:ip:1.1.1.1server2:ip:1.1.1.2 Modify Server1 configuration file vim/etc/my.cnf[mysqld]vim /etc/my.cnfdatadir=/var/lib/mysqlsocket=/var/lib/mysql/mysql.socksymbolic-links=0log-error=/var/log/mysqld.logpid-file=/var/run/mysqld/mysqld.pidlog_bin=

Mysql recursive queryDefinition: Parent-Child query: query all the following child node data according to the parent ID; child Parent query: query all the parent node data according to the child ID;1 Creating a TableDROP TABLE IF EXISTS' shop

# SQL statement Optimization>1) Limit the amount of data that is queried once2) Link query instead of subquery3) Try not to use SELECT * To list the fields you need to find4) If the amount of data is particularly large, try to split a complex SQL

1. Export all databasesUse Mysqldump's-all-databases parameter to export all the databases under your database root to a SQL file in one breath. Then, after reloading the system, use the source command to rewind back in a breath.You need to

When we use MySQL, we often need to change the root user password for different reasons, this blog mainly describes several ways to modify the root user password. Before the root password is set: How to SET the password command:mysql

First, the grammar Select Grouping function, after grouping field from table "where filter Condition" Group by Group Field "Having group filter" "Order by Sort List" Second, the characteristicsPre-grouping filter: Where-original

First, the application scenarioWhen the number of entries to be queried is too many, one page is not fully displayedSecond, the grammarSelect query list from table limit "offset," size;2.1. Note:Ffset represents the starting entry index, which

Today, there is a requirement to import data from one table to another table using automatic tasks. Specific scenarios and limitations: Import data from Table a in database a into table B of database B (either incremental or full data); System 1