Mysql存储过程查询结果赋值到变量

DECLARE cnt INT DEFAULT 0;
select count(*) into cnt from test_tbl;
select cnt;

set @cnt = (select count(*) from test_tbl);
select @cnt;

select count(*) into @cnt1 from test_tbl;
select @cnt1;

select max(status), avg(status) into @max, @avg from test_tbl;
select @max, @avg;