Question

我希望根据这些列从我的数据库表中获取重复的行：TaskID，StudentID，DateChanged

请让我知道如何查询这个。感谢

Answer 1

试试这个

      SELECT Taskid, Studentid, DateChangeid
      FROM Table1
      GROUP BY Taskid, studentid, datechangeid
      HAVING COUNT(*) > 1

如果您想显示所有字段，请尝试此

SELECT *
FROM Table1 t
JOIN (  SELECT Taskid, Studentid, DateChangeid
      FROM Table1
      GROUP BY Taskid, studentid, datechangeid
      HAVING COUNT(*) > 1) temp
  ON t.taskid = temp.taskid AND t.studentid= temp.studentid AND t.datechangeid= temp.datechangeid

Answer 2

根据您的描述，我认为这就是您所需要的：

SELECT *
FROM Table1
WHERE TASKID = 'TaskID1'
AND StudentId = 'StudentID1'
AND DateChanged = 'DateChanged1'

如何根据几个列值获取重复行？

2 个答案: