Mysql common SQL statements (1) and mysqlsql statements

Mysql common SQL statements (1) and mysqlsql statements
[1] Clear TABLE statement

truncate table fke_message;

[2] resetting the start value of the auto-increment Field

alter table fke_message auto_increment = 10001;

[3] common table creation statements

Drop table if exists 'fke _ message'; create table 'fke _ message' ('id' int (10) not null AUTO_INCREMENT, 'username' varchar (40) not null default ''comment 'username', 'tel 'varchar (20) not null default ''comment 'phone number', 'email 'varchar (40) not null default ''comment' email address, 'msginfo' varchar (255) not null default ''comment' message ', 'createdate' int (11) not null default '0' comment' timestamp ', primary key ('id') ENGINE = InnoDB default charset = utf8;

[4] common query statements

1. count the number of users

select count(distinct id) from fke_member

2. Add Fields

alter table e_down add soft_version1 varchar(50) NOT NULL default '' ;

3. Modify the field type

alter table address modify column city varchar(50) NOT NULL default '';

4. Add an index

alter table member add index id_index(id);

[5] database creation statement

create database test default CHARACTER SET utf8 COLLATE utf8_general_ci;