* Yuen-Jeong Kim > I read from online manual : > > ============================================================= > KEY is normally a synonym for INDEX. From version 4.1, the key attribute > PRIMARY KEY may also be specified as just KEY. This was implemented for > compatibility with other databases > ============================================================= > > But I think maybe KEY and INDEX same practically. > > If keys and indexes are not same, Could anyone let me know what > is different between KEY and INDEX ??
KEY and INDEX is the same, the above excerpt from the manual is about the "PRIMARY KEY" attribute used in a field definition. From 4.1 this is legal for creating a primary key: CREATE TABLE t1 (id int not null KEY,data varchar(255)); Before 4.1 you had to do this: CREATE TABLE t1 (id int not null PRIMARY KEY,data varchar(255)); You can NOT do the following to make a primary key in 4.1: CREATE TABLE t1 ( id int not null, data varchar(255), KEY (id)); The key on 'id' will of course be a normal non-unique index in this case. -- Roger -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
