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