c# - 子查询返回多于 1 行

Question

我有这个问题:

UPDATE student_info 
    set grade = (SELECT tempTable.grade 
                     FROM tempTable
                     WHERE student_info.s_id = (SELECT s_id FROM tempTable))

我也在这里尝试了建议的解决方案: http://dev.mysql.com/doc/refman/5.0/en/subquery-errors.html

Answer 1

我猜你想要:

UPDATE student_info 
  JOIN tempTable
    ON tempTable.s_id = student_info.s_id 
SET student_info.grade = tempTable.grade