MySQL Common SQL statement (i)

"1" EMPTY table statement

TRUNCATE TABLE fke_message;

"2" resets the starting value of the Increment field

ALTER TABLE fke_message auto_increment = 10001;

"3" common build Table Statement

DROP TABLE IF EXISTS ' fke_message '; CREATE TABLE ' fke_message ' (  ' id ' int () NOT NULL auto_increment,  ' username ' varchar (+) NOT null DEFAULT ' COMM ENT ' username ',  ' tel ' varchar (a) NOT null default ' COMMENT ' phone number ',  ' email ' varchar (+) NOT null default ' ' COMMENT ' e-mail ',  ' msginfo ' varchar (255) NOT null default ' COMMENT ' message ',  ' createdate ' int (one) not null default ' 0 ' commen T ' timestamp ',  PRIMARY KEY (' id ')) engine=innodb DEFAULT Charset=utf8;

"4" Common query statements

1. Statistics User Volume

Select COUNT (Distinct ID) from Fke_member

2. Add Fields

ALTER TABLE E_down add soft_version1 varchar (+) not NULL default ';

3. Modify the field type

ALTER TABLE address modify column city varchar (n) 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;

MySQL Common SQL statement (i)