我是 Mysql 循环的新手,网上似乎没有太多关于它们的信息。我已经搜索过了,但什么也做不了。有人可以帮忙吗,这是代码
PROCEDURE while_loop()
BEGIN
SET @var_number_of_departments = (SELECT COUNT(DISTINCT departmentid) FROM employees); -- finds number of departments
SET @var_departmentid = 1; -- sets incrementing value to 1
WHILE @var_number_of_departments > @var_departmentid DO -- loop until all departments have been analyzed
SELECT Name FROM employees WHERE BossID IS NULL AND departmentid = @var_departmentid AND salary > (SELECT salary FROM employees WHERE bossID IS NOT NULL AND DepartmentID = @var_departmentid);
SET @var_departmentid = @var_departmentid + '1'; -- increment value in order to analyze the next department
end while;
end;