加入两张 table

2 回答

• 2

  试试这个未经测试的查询：

  select t1.AttendanceDate, t1.EmployeeCode, case when t2.duration is null then t1.duration else t2.duration end 
  from table1 t1 left outer join table t2 on t1.AttendanceDate= t2.AttendanceDate and  t1.EmployeeCode =  t2.EmployeeCode
  

  回复于 2024-05-21T10:30:20+08:00
• -1

  这应该工作 .

  SELECT Table1.AtendanceDate, Table1.EmployeeCode,
      CASE WHEN Table2.Duration IS NOT NULL THEN Table2.Duration ELSE Table1.Duration END AS Duration
  FROM Table1 
  LEFT OUTER JOIN Table2 ON Table1.AtendanceDate = Table2.AtendanceDate 
      AND Table1.EmployeeCOde = Table2.EmployeeCode
  

  回复于 2024-05-21T10:30:20+08:00