SQL inset into 语句中where出错，谢谢

INSERT INTO Tab_Checksum ([name],checkdate,startclass,finishclass,later,absenteeism,early,normal)
SELECT [name],
checkdate,
SUM(startclass) startclass,
SUM(finishclass) finishclass,
SUM(later) later,
SUM(absenteeism) absenteeism,
SUM(startclass)+SUM(later)-SUM(finishclass) early,
SUM(finishclass)-SUM(later)
FROM Tab_Check
where Tab_Checksum.checkdate != Tab_check.checkdate//错误行

  GROUP BY [name],checkdate
  ORDER BY [name],checkdate

错误 无法绑定由多个部分组成的标识符 "Tab_Checksum.checkdate"。

你这是Insert语句，select中Tab_Checksum.checkdate != Tab_check.checkdate是不对的，访问不到Tab_Checksum表

你应该用

 not exists(select top 1 1 from Tab_Checksum where Tab_Checksum.checkdate = Tab_check.checkdate)