MySQL

MySQL Database Delete and changeAdd :CREATE Database DBname charset GBK; Delete: Drop database  dbname; : alter database dbname charset  GBK ;  renamed: The following check : show databases; (show databases like '%name ';) Check:

In our actual business of writing code, sometimes the entity class uses string, the database is naturally a varchar type, but if the attribute value of this entity is a numeric type, you need to sort it when you query. SQL how to write it.Don't

Mysql provides two built-in functions that let us use the cast () and CONVERT () functions, respectively: Cast and Convert,mysql, to convert or obtain a type that we need. The specific syntax for both is as follows:(1) Cast (value as type);(2)

Detects if an event is turned onCopy CodeThe code is as follows:Show variables like ' Event_scheduler ';2. Turn on eventsCopy CodeThe code is as follows:Set global Event_scheduler = on;3. Create a stored procedureCopy CodeThe code is as

-  increase insert into ... values (...)  insert into  table name; values () to include all data; insert into  the table name (field); values () only need to enumerate the corresponding data;|  Full column Insert Insert into studentsvalues (0, ' Guo

-  Basic Query |  query all columns  select * from students;|  Specify criteria query  select * from  students where is_delete=1;|  query a specified column  select name, gender from  The order of the students;|  fields

-  The function that creates-- sql must have a return value-- create function  function name (argument list)  returns  return type create  FUNCTIONF1 ()  returns intreturn 10;-  view--  View  mysql.proc    select db,name,type from mysql.proc;-  Call-

-Data type principle try to use a small range of values to save storage space integer: int, bit decimal: decimal denotes floating-point number decimal (5, 2) a total of 5 digits, and decimals is a 2-bit string: varchar (variable-length string), char

DirectoryI. OverviewSecond, MySQL installationThird, successful installation verificationIv. navicatformysql Download and useI. OverviewMySQL version: 5.7.17: Http://rj.baidu.com/soft/detail/12585.html?aldClient Tools: NavicatformysqlGreen version:

#1 operating folders (libraries)Add CREATE Database db1 charset UTF8; Check show databases; Show CREATE Database db1; Change ALTER DATABASE DB1 CharSet GBK; Delete drop database db1;#2 Operation files (table)Switch to Folder: Use DB1

1. Create custom DatabaseCreate database custom;2. Create a Cuser tableCREATE TABLE Cuser (ID int unsigned auto_increment primary key,Account varchar (#) is not NULL,Password varchar () NOT NULL,Username varchar () NOT NULL,card_id varchar () NOT

1. Enter the MySQL configuration directory to allow other IPs to linkVI/ETC/MYSQL/MYSQL.CONF.D/MYSQLD.CNF, the following line commented out #bind-address = 127.0.0.12, remote connection or failure, view log discovery will visit IP to find

Operation of the data: additional Search and deletionLevel of data manipulation: operation of library data, operation of table data, and operation of table segment data.　　Library-level operations:　　1 add: Create Database db1; 2 switch database

warning:world-writable config file '/applications/xampp/xamppfiles/etc/my.cnf ' is ignoredERROR 2002 (HY000): Can ' t connect to local MySQL server through socket '/applications/xampp/xamppfiles/var/mysql/mysql.so CK ' ("Connection

First we need to install vc++2013 otherwise it may appear and cannot find the Msvcr110.dll filehttp://www.microsoft.com/zh-cn/download/details.aspx?id=407841. Download (operating system for Windows Server 2016 Datacenter

#!/bin/shMysqlport= ' Netstat-na|grep "LISTEN" |grep "3306" |awk-f[: ""]+ ' {print $} 'mysqlip= ' ifconfig eth0|grep "inet addr" | awk-f[: ""]+ ' {print $4} 'status=$ (/usr/local/mysql/bin/mysql-e "show slave status\g" | grep-i "Running")Io_env= '

Read Catalogue A knowledge reserve Two initial knowledge of SQL language Three-system database Four Create a database Five Database related operations A knowledge reserveMySQL database basic Operation knowledge

1) The LEFT join is the rightEven if you think you have a deep understanding of MySQL's left JOIN, I bet this article will make you learn something! The ON clause differs from the WHERE clause A better understanding with WHERE ... A

MySQL and other databases have views-view,view is not a real table, it is actually through the select query out of the projection (results) as a table to query, in the view is actually stored in a pre-written SELECT statement, This allows you to

MariaDB Experience 1 ---- database installation, mariadb1 ---- Database Microsoft SQL Server database, which has been used for a long time, is now used for data analysis. Just as the company was upgrading its cloud architecture and selecting