MySQL uses the underlying SQL statement (i)

The command line input mysql-u root-p, enter the password again, enters MySQL.

The terminal command ends with a semicolon as a statement, and can be divided into multiple lines of input, with only a semicolon at the end. Such as:

I.DDL: Data definition language Language
　　

　　Role: Defines a database or table structure.

　　object to manipulate: the structure of a database or table.

　　Keyword: CREATE ALTER DROP

① Querying the database:

the display currently has several libraries, input: mysql>show DATABASES;

② Create a database:

Create a database called MYDB1: mysql>CREATE DATABASE mydb1;

View Database creation details:mysql>show Create database mydb1;

Create a MYDB2 database that uses the GBK character set: mysql>create db mydb2 CHARACTER SET GBK;

Create a MYDB3 database that uses the GBK character set with proofing rules: mysql>create db mydb3 CHARACTER SET GBK COLLATE gbk_chinese_ci;

③ Deleting a database:

Delete the previously created MYDB3 database: mysql>DROP db mydb3;

for the operation of a database, assume that the database is test:

The first thing to choose is the database: mysql> use test;

① Display the table information:

Show all tables in the current database: mysql>show TABLES;　

to view the definition of a table structure: Mysql>desc employee;　

View the table's creation details: mysql>SHOW create table user;

② Create a table:

Create a table of employees:

Mysql>CREATE TABLEEmployee (IDint, namevarchar( $), Gendervarchar(Ten), Birthday date, entry_date date, Jobvarchar( $), Salaryfloat(8,2), Resumetext);

③ Modify the table:　

An image column is basically added to the employee table above : MySQL>ALTER table employee ADD image blob;

View the definition of a table structure: mysql>DESC employee;

Modify the job column to a length of: mysql>ALTER TABLE employee MODIFY job varchar(60 );

Delete image column: mysql>ALTER TABLE employee DROP image;

Table name changed to User: mysql>RENAME table employee to user;

Modify the table's character set to GBK: mysql>ALTER table user CHARACTER set GBK;

Column Name name modified to username: mysql>ALTER TABLE user change name username varchar (a);

④ Delete Table:

Delete Table Employee: drop table employee;　　

MySQL uses the underlying SQL statement (i)