MySQL Modify Add Delete table field

Add a field to a table ALTER TABLE name the type of the Add Field name fields

Example: ALTER TABLE table1 add transactor varchar (ten) not Null;

ALTER TABLE table1 add ID int unsigned not Null auto_increment primary key

How to add a field after a specified field in the MySQL database:

ALTER TABLE Newexample add address varchar (a) after stu_id;

Modifying the field type of a table ALTER table name MODIFY COLUMN field type definition;

Example: ALTER TABLE chatter_users MODIFY COLUMN IP VARCHAR (50);

Modify the field name of the table ALTER TABLE name change the original field name the type of the new field name segment

example: ALTER TABLE student change Physics Physisc char (TEN) NOT NULL

Delete a table field ALTER TABLE name drop column field name

Example: Alter TABLE ' user_movement_log ' drop column Gatewayid

Adjust table order: ALTER table ' user_movement_log ' change ' Gatewayid ' gatewayid ' int not null default 0 after RegionID

table rename ALTER TABLE name rename present table name;

Example: ALTER TABLE t1 rename T2;

Delete table data Delete from table name where (condition) ID is not starting from 1, TRUNCATE table name ID is starting from 1

Example of creating a table

CREATE TABLE hlh_message (

ID Int (one) not NULL auto_increment COMMENT ' health table ID ',

Title varchar (+) not NULL COMMENT ' health title ',

Hlh_url text DEFAULT NULL COMMENT ' picture address ',

BeWrite VARCHAR () not NULL COMMENT ' description ',

Content VARCHAR (+) not NULL COMMENT ' contents ',

Type tinyint (1) Not NULL DEFAULT ' 0 ' COMMENT ' health Knowledge 0 Health Consulting 1 ',

Create_time date DEFAULT NULL COMMENT ' time to publish message ',

PRIMARY KEY (ID)

) Engine=innodb DEFAULT Charset=utf8 comment= ' health table '

MySQL Modify Add Delete table field