MySQL

MySQL database installation tutorial and related issues2018-07-13MySQL database download and installation tutorialProblem 1:mysql Remote Connection Host * is not allowed to connect to this MySQL serverMySQL 8.0 Command Line Client-unicode

MySQL service usage1. Start the serviceStart the service:Service MySQL StartOrSudo/etc/init.d/mysql start2. Close the serviceTo close the service:Service MySQL StopOrMysqladmin-u root-p shutdownAnd then look at the discovery, the database is

1.innerjoin (internal connection, or equivalent connection)select * from table1 inner join table2 on table1.column1= table2.column2;2.left join (left connection)select * from table1left join table2 on table1.column1= table2.column2;3.right Join

The Find_in_set function in MySQL is interesting, and its function is to find a comma-separated value, we can store the data like the 1,2,3,4 format. Today we'll look at how to correctly use the Find_in_set function for data query in thinkphp.In

1. View slave statusshow slave status\G2, stop slave State, clear the master-slave information from the librarystop slave；reset slave all;3. Deleted from library synchronized main library databaseDROP DATATBASE DBNAME;4. Backing up primary database

MySQL in Myisam,innodb by default is the Btree index, as to how the data structure of btree is not important,Only need to know the result, since is the index that this data structure finally is orderly, like Xinhua dictionary His directory is

A constraint is a restriction that ensures the integrity and uniqueness of a table's data by restricting the data on the table's Rows or columnsConstraint classification:Constraint types and keywords: Primary KEY PRIMARY Key Default

Today, colleagues encountered a problem, wrote a paging function, the results found that the data has been duplicated, some data at the same time in the adjacent two pages appear,But the query total data is not paged when there is only one, here is

A test virtual machine installed MySQL accidentally crippled by me, now want to completely clean it off. System environment: CENTOS7, MySQL If the MySQL service is in the boot, you need to stop Systemctl Stop MysqldOrService

The first step: Download https://dev.mysql.com/downloads/mysql/on the websiteStep Two: Extract to a folderStep Three: Configure environment variablesTo insert a%mysql_home%\bin into the last face of a path.Fourth step: Run the command line as an

MySQL master-slave copy and read/write separate MySQL read and write separation principle Read-write separation is only written on the primary server and is read only from the server. This is based on the principle that the primary database

Find your own MySQL installation directory, find My.ini, in the [MYSQLD] Paragraph add a sentence: Skip-grant-tables (role is to skip the user login process, directly log on to MySQL)You can then log in to MySQL in CMD andmysql> use MySQL;  mysql>

One, data insertion operation1.1 Inserting data into a specified field in a tableSyntax:INSERT INTO table name (Field 1, Field 2,...) VALUES (Value of field 1, Value of field 2,...);Note: The list of values in 1.values needs to correspond to the

To inquire the records of the top three grades of each section without regard to the situation of juxtaposition;SelectA.COURSE_ID as Course ID,A.score as scores,Count (a.course_id) as rankingFrom score a LEFT JOIN score B on a.course_id=b.course_id

MySQL database itself provides the master-slave replication function can easily achieve multiple automatic data backup, to achieve the expansion of the database. Replication between MySQL is based on binary log files, a MySQL database once the

MySQL backup can be divided into cold backup and hot backup two kinds.Cold backup: Stop the database service for backupHot backup: Do not stop the database service for backupMySQL storage engine for MyISAM, only support cold backup, you can directly

Non-null constraintCREATE TABLE USER ( INTnotNULL,-- non-null constraint VARCHAR(10 ), VARCHAR(DEFAULT' Shandong province ' -- default value )Unique constraintCREATE TABLE USER ( INTunique,-- Unique constraint VARCHAR() ,

There are several times in MySQL: Date, time, DateTime, timestamp, yearMySQL data type meaningDate only stored date, ' 2018-07-12 'Time is stored only seconds and minutes, ' 09:51:02 'DateTime storage Month day minute minute, ' 2018-07-12 09:51:02

The error is as follows, Access denied for user ' root ' @ ' localhost ' (using passwordTurn off the MySQL service and restartIf not, that should be the password is changed, the password does not correspond1. Run cmd as a system administrator.2.

First, the database operation:1. View the database:>show DATABASES;2. Create a database:>create DATABASE db_name; Db_name for Database name3. Use the database:>use db_name;4. Delete the database:>drop DATABASE db_name;Second, create the table:1.