Question

sql中怎样知道Select查询出的结果一共有多少行

比如select * from tablename;
怎样获取查询结果的行数；

Answer 1

执行语句后,跟着执行下面语句就可以知道了:
select @@rowcount

当然，也可以直接:
select count(*) from tablename

Answer 2

select count(*) from tablename

Answer 3

select count（*） from tablename

Answer 4

SELECT *, (select count(*) from from tablename ) as Count FROM from tablename