MySQL

The data in the original table is not encrypted, creating an encrypted table, looping the data inside the original table, and inserting it into the encrypted table after encryption. Finally, a trigger is created that inserts data into the original

Common commandsPrinciple: Use the tool as much as possible with the visualizer, and the command line is limited to troubleshooting.mysql -u ACCOUNT -pPWD -h IP -P port [-D database] //连接数据库show databases; //显示数据库列表use db_name; //使用数据库show tables;

The select sentence that appears in other SQL statements. (Nested select in select)#求出学生的平均年龄Select AVG (age) from Stu_details;#查找出大于平均年龄的数据Mysql> SELECT * from Stu_details where >18.25;#将平均数的SQL语句作为子查询放入上一条语句中Mysql> SELECT * from Stu_details where >

Rights Management:We know that our top authority manager is the root user, and it has the highest permissions. Includes select, Update, delete, update, Grant, and so on. So in general, after the company, the DBA engineer creates a user and password

Create VIEW will have definer= admin @ localhost can be modified by navicat, design view-->adanced ModifyCreate function will have definer= admin @ localhost can be modified by Navicat, double-click function-->adanced ModifyStored procedure will

For operations personnel, responsible for the application system more and more, to manage more databases, how to solve the problem of forgetting the MySQL super Administrator password? We can skip the permission table by adding

Before SQL Server row to column, you can use pivot to write.Refer to this article https://www.cnblogs.com/gaizai/p/3753296.htmlAccording to the actual table of your project, change to thisCREATE PROCEDURE [dbo]. [Usp_crmbaseinfo]--Add The parameters

This article is compiled from "MySQL Technology insider InnoDB storage Engine"MySQL through the background of various threads, memory pool, file interaction to achieve external services, different threads to achieve different resource operations,

1. DownloadDatabase: Mysql-3.23.53-win1Visualization tool: Mysqlcc-0.9.4-win322. Steps:(1) Decompression mysql-3.23.53-win1 (others can also), follow the steps to install to your local, install and find the path of the bin folder and copy it down;(2)

1. Docker search and download MySQL imageDocker search MySQL;Docker Pull mysql:5.7 (5.7: Version number);2. Create a MySQL image and runDocker run --name you-mysql-p 3308:3306-e mysql_root_password=123456-d MySQLTerminal authorization to enter MySQL

# # #开发规范Development specification: keyword capitalization, library name lowercase, to have character setCREATE databse oldboy CHARSET UTF8; # # #建议采用第一种CREATE databse Oldboy CHARSET utf8mb4;# # #lower_case_table_names begin###Mysql> Show variables

KEY_BUFFER_SIZE Specifies the size of the index buffer, which determines the speed of index processing, especially the speed of index reads. By checking the status values key_read_requests and Key_reads, you can know if the key_buffer_size setting

Delete a database tabledrop table [if exists] table I, table two ...;Table partitioning: There are 10 million books in the book Information table, how to optimize him, one of the ways is table partitioning. is to divide the data of a table into

of the MySQL databaseExport1. Export the database as a SQL fileMysqldump database name-uroot-p > XXX.SQL Export data table structure and dataeg. Mysqldump cloudres-uroot-p > Cloudres.sql2. Export to GZ compressed fileMysqldump Database name-uroot-p |

1 MySQL master-slave synchronization, prepare 2 servers, already installed MySQLMaster: mysql1:192.168.12.101From: mysql2:192.168.12.1022 master-Slave synchronization requires the Binl-og log to be turned on and the library from MYSQL2 needs to be

1,group by creating a groupIn MySQL group by sentence to note that must after where the order bySelect Order_code, COUNT (*) as product from order group by Order_code;2,having Packet filteringThe WHERE clause can be replaced by the having, the

I have a Linux dish, only learn and record the memo hereFirst, the installation is divided into three steps:1, wget-i-C http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm2, yum-y install mysql57-community-release-el7-10.noarch.rpm3,

 　　installation Yum Install Mysql-serverChkconfig-list mysqld to see if the MYSQLD service is booting upchkconfig mysqld on set to bootService mysqld start mysqld ServicesSs-ntl (3306) after automatic completion, the corresponding port automatically

Clustered indexA clustered index is not a separate index type, but rather a way of storing data (not a structure, but a storage structure), and the details depend on how it is implemented, and the clustered index actually holds the Btree index and

Data types: Data columns, stored procedure parameters, expressions, and data characteristics of local variables.Plastic:tinyint: One byte, 128 to 127;2 7-Time SquareSmallInt: Two bytes, 32768 to 32767;2 15-Time SquareMediuint: Three bytes, 8388608