mysql给表增加rowid

create table score
(
    id    int         null,
    yuwen varchar(20) null
);
# 插入数据
INSERT INTO score (id,yuwen) VALUES (1,'82');
INSERT INTO score (id,yuwen) VALUES (2,'63');
INSERT INTO score (id,yuwen) VALUES (3,'74');
INSERT INTO score (id,yuwen) VALUES (2,'63');
INSERT INTO score (id,yuwen) VALUES (3,'74');
INSERT INTO score (id,yuwen) VALUES (1,'82');
INSERT INTO score (id,yuwen) VALUES (3,'74');

select @rowid:=@rowid+1 as rownum, b.* from (select @rowid:=0) a, score b;