MySQL DLL Statement

Tags: mysql database/dba/Delete database tables

Overview

Because there are some things, from the publication of an article to the middle of the current interval of several months, in the following time will be published on some of the MySQL articles, from the base to the optimization of the final to management, welcome to the discussion.

Body

Create a database

CREATE DATABASE DBNAME;

Deleting a database

DROP DATABASE DBNAME;

Show All Tables

Show tables;

Create a table

CREATE TABLE TABLENAME (clumn clu_len)

CREATE TABLE  INT(tennotNULLVARCHAR); -- defining the int type in MySQL syntax you can add the length of the field type after the parentheses, if not the length of int (11).

Self-increment column (auto_increment)

CREATE TABLE AI (ID INT auto_increment not NULL PRIMARY KEY);

List table Definitions

DESC TABLE;

View statements that create a table

Grammar show CREATE TABLE tablename;

TABLE USER \g;

Change table name

ALTER talbe tablename RENAME new_tablename

modifying field types

ALTER TABLE [COLUMN] [First| After Col_name]-- Modify the field name (The new field must be with the field type)

Rename Field

ALTER TABLE [COLUMN] [first| After Col_name]

Add Field

--GrammarALTER TABLETableNameADD [COLUMN]Column_definition[First | After Col_name]--Add a default Value fieldALTER TABLE User ADDAgeINT  not NULL DEFAULT 0;
---self-increment
Auto_increment

Add the default value in MySQL cannot be preceded with ' () ', if the shape field is a direct space plus the value to be set, if the character field is a single quote ', this is different from SQL Server

Delete a field

ALTER TABLE DROP [COLUMN] col_name

Delete a table

DROP TABLE TableName

Summary

The DDL statement about MySQL is relatively simple, with some details on the syntax, and no syntax to remember.

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MySQL DLL Statement