MySQL table-level SQL statements

CREATE TABLE table_name (

ID int unsigned primary key auto_increment,

Username varchar (+) NOT NULL,

Nickname varchar (+) NOT null default ' anonymous ',

Unique key (username)

);

CREATE TABLE IF not EXISTS ' test ' (
' id ' int (ten) unsigned not NULL auto_increment,
' Nickname ' varchar (+) not NULL DEFAULT ' anonymous ',
PRIMARY KEY (' id '),
KEY ' nickname ' (' nickname ')
) Engine=myisam DEFAULT Charset=utf8 auto_increment=1;

Index additions and deletions: (the index name is usually the same as the field name)

ALTER TABLE name Add primary key (' field List '); Add primary Key

ALTER TABLE name drop PRIMARY key; Delete primary Key

ALTER TABLE name add unique key index name ( field List ); Add a unique index, example:

ALTER TABLE ' test ' ADD UNIQUE (
' Username '
);

ALTER TABLE name DROP INDEX index_name; To delete a unique index, for example:

ALTER TABLE ' test ' DROP INDEX ' username ';

alter  table   ' test '   add  index  (  ' nickname '  

ALTER TABLE ' Test ' drop index ' nickname ';//delete normal index