Database manipulation language DML; database query Language DQL; Database schema definition language DDL; Database control Language DCL; DDL database schema definition language View all the user's database, show databases; the command to delete the database is: Drop the database name; Finally, the database switch, the command is: Use database name, 2.DDL operation table, mainly including the creation of tables, Modifications, deletions, and so on. The modification of the table includes adding and subtracting columns, modifying columns, modifying table names, and so on. First of all, the need to use ethics to query the database of all the operations of the table, the command is: show tables; the command to view the table structure is: DESC table name; add column command: ALTER TABLE name add new column name, delete column command: ALTER TABLE Table name drop column name; the command to modify the column type is: ALTER TABLE name modify column name is the new type; the command to modify column names is: ALTER TABLE table name change column name new column name new column type; To a new table name; the command to delete a table is: drop table name; ========================================================================================= DML Database Manipulation Language DQL database query Language DCL Database control language
MySQL Operating language
