MySQL

sudo password create a new root password:1, open the terminal with the current login user, in the terminal input command sudo passwd, enter the current user's password and then return2, will be prompted to enter a new password, enter the completion

I recently read a book about MySQL "MySQL must Know", the book only a few basic knowledge, but also basically covers all the MySQL knowledge points. The rest of the more advanced also only on the basis of expansion or optimization, after reading

1. Check the book price, if the price is null, then show unknown, if the price is 10 to 20, then show the 20SELECT price,case when price= ' null ' then ' Unknow ' when the price>10 and price2.Select name, case if birthday ' 1988 ' Then '

Data integrity　　Entity integrityEntity: A row in a table (a row of records) instead of an entityThe role of entity integrity: identifies each row of data that is not duplicated.Constraint type: PRIMARY KEY constraint, UNIQUE constraint, auto-Grow

Http://blog.sina.com.cn/s/blog_767d65530101861c.htmlhttp://blog.csdn.net/kaihuishang666/article/details/74407972http://blog.csdn.net/dehu_zhou/article/details/52881587Data Type--decimalThe declaration syntax for a column is DECIMAL (m,d).Ifnull

PackageCom.swift;//The package imported here is java.sql.Connection instead of Com.mysql.jdbc.ConnectionImportjava.sql.Connection;ImportJava.sql.DriverManager;Importjava.sql.SQLException; Public classTESTJDBC { Public Static voidMain (string[] args)

The following is the message that prompts after normal initialization, this article is very important[Email protected] scripts]#/mysql_install_db--basedir=/application/mysql--datadir=/application/mysql/data/-- User=mysql# #指定mysql安装路径, specify the

First, the index optimization principle 1, the leftmost prefix matching principle, the joint index, MySQL will match from do right until encounters the scope query (>, 3 and D = 4 if established (A, B,C,D) The index of the order, D is not indexed,

1: Query out the required column names for backup#列名Select column_name from Information_schema.columnswhere table_schema= ' yunpiaobox_db ' and table_name= ' T_box_status 'TABLE_SCHEMA: Database name table_name: Table name#列名字符串 Press,

1 Drop PROCEDURE IF EXISTSAddisdoliday;2 CREATE PROCEDUREAddisdoliday ()3 BEGIN4 IF not EXISTS(SELECT * fromInformation_schema.columnsWHERETable_schema= DATABASE() andtable_name= 't_fee_static' andcolumn_name= 'Isdoliday') Then5 ALTER

This is a really big hole. TM Toss an afternoon finally got it. Quickly record and share to everyone, lest have and I have been configured not successful and toss half a day ....1. Installing MySQL for Visual StudioThis will be downloaded and

1. Check if MySQL is installed in the current environmentRpm-qa | grep MySQL2. Install MySQLYum Install-y mysql-server3. Start the MySQL serviceService mysqld Start4. Set the password for the MySQL administrator usermysqladmin-u root password ' 12345

The main master replication of MySQL is two MySQL nodes, mainly from each other. It is very easy to build up MySQL master-slave and then build the main master copy.Video link: http://www.roncoo.com/course/view/658088f6e77541f5835b61800314083eOn the

1. Create a table templateSET foreign_key_checks=0;DROP TABLE IF EXISTS ' g_test ';CREATE TABLE ' G_test ' (' id ' int (one) unsigned not NULL auto_increment COMMENT ' id ',' Update_time ' timestamp NULL DEFAULT current_timestamp COMMENT ' Update

1. Installation Issues Generally I will go to the official website to download software, but this MySQL official website will ask you to have what environment, need to download something and so on to you to install. Perhaps our computer

A: MySQL Permissions table user field in detail:Select_priv. Determines whether the user can select data through the Select command.Insert_priv. Determines whether the user can insert data through the Insert command.Update_priv. Determines whether

There are many versions of Linux, so when downloading MySQL, it is important to download the MySQL database file corresponding to the Linux version. The following methods are also suitable for installing the MySQL 5.7.* version of CentOS 7. The

Simple MySQL knowledge and simple MySQL knowledge I recently read a book on MySQL, which only describes some basic knowledge, but also covers all MySQL knowledge points. The rest of the more advanced ones are only extended or optimized on the basis.

Stored Procedure cursor error handling (regenerate user ID), stored procedure user ID -- Set_account_data regenerate user id begin declare temp_id INT (8);/* User id */DECLARE temp_manager INT (8);/* parent id */DECLARE temp_accounter_no VARCHAR (64

[Personal notes] Three relationships: one-to-one, one-to-many, and many-to-many ., Zhijintang: one-to-one   One-to-one: for example, a student corresponds to an ID card number and student archive; One-to-many: A class can have many students, but one