Primary use of MySQL

One: Simple use of MySQL

1. Today to record common SQL commands

View Gallery show databases;

view table show tables;

Enter library use library name;

Create a new library create database name;

Create a new table the CREATE table library name. Table Name (field type (width) constraint); (You can omit the library name when in the library)

eg

　

1 start creating the first table DB1, and view the table structure

2 Insert the first value into the table and use the command to view

3 Append a field in the DB1 table

4 Modifying the value of age

SQL statement used:

Modify table structure: Alter tables library. Table Execution Action

Execution actions include:

{add: Add, modify field type and constraint: Modify, modify field name: Change, modify table name: Rename, delete: Drop}

ALTER TABLE Add|modify|change|rename

ALTER TABLE DB1 add age int (2); [Firsh|after: Specify where to insert]

ALTER TABLE DB1 Modify field Name type (width) constraint;

ALTER TABLE DB1 change original field name New name type (immutable) constraint (variable);

ALTER TABLE DB1 Rename the name of the new table with the original table name;

ALTER TABLE DB1 drop field

Primary use of MySQL