获取错误#1221 - UNION和LIMIT的使用不正确

Question

我正在尝试使用查询union之间的这两个查询进行联合查询但是收到错误#121 UNION和LIMIT的使用不正确.请帮我制作这个联合查询以获得这些查询的结果.

QUERY1:

SELECT t1.TraineeID,
       t2.attnDate,
       MIN(t1.attnTime) AS inTime,
       (CASE WHEN MIN(t1.attnTime) < MAX(t1.attnTime) THEN MAX(t1.attnTime) else '' end) AS outTime,
       (CASE WHEN t5.Slot ='1' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '1')THEN 'P' 
             WHEN t5.Slot ='2' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '2')THEN 'P'
             WHEN t5.Slot ='3' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '3')THEN 'P'
             WHEN t5.Slot ='4' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '4')THEN 'P'
             WHEN t5.Slot ='1' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '1')THEN 'Early Out' 
             WHEN t5.Slot ='2' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '2')THEN 'Early Out'
             WHEN t5.Slot ='3' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '3')THEN 'Early Out'
             WHEN t5.Slot ='4' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '4')THEN 'Early Out'
             ELSE 'Late-In'
       END) AS Status

FROM tbl_attn_temp t1, tbl_assigned t3, tbl_batch t5
JOIN (SELECT DISTINCT attnDate FROM tbl_attn_temp) t2
WHERE t1.attndate = t2.attnDate and t3.BatchID=t5.BatchID AND t1.TraineeID = t3.TraineeID
AND t1.attnDate='2016-01-13'
AND(CASE WHEN t5.Slot ='1' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '1') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '1') 
         WHEN t5.Slot ='2' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '2') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '2')
         WHEN t5.Slot ='3' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '3') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '3')
         WHEN t5.Slot ='4' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '4') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '4')
    END)
GROUP BY t1.TraineeID, t2.attnDate

QUERY2:

SELECT t1.TraineeID,
       t2.attnDate,
       MIN(t1.attnTime) AS inTime,
              (CASE WHEN MIN(t1.attnTime) < MAX(t1.attnTime) THEN MAX(t1.attnTime) else '' end) AS outTime,
       (CASE WHEN t4.Slot ='1' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '1')THEN 'P' 
             WHEN t4.Slot ='2' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '2')THEN 'P'
             WHEN t4.Slot ='3' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '3')THEN 'P'
             WHEN t4.Slot ='4' AND t1.attnTime<=(SELECT inTime FROM tbl_threshold WHERE id = '4')THEN 'P'
             WHEN t4.Slot ='1' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '1')THEN 'Early Out' 
             WHEN t4.Slot ='2' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '2')THEN 'Early Out'
             WHEN t4.Slot ='3' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '3')THEN 'Early Out'
             WHEN t4.Slot ='4' AND max(t1.attnTime)<(SELECT outTime FROM tbl_threshold WHERE id = '4')THEN 'Early Out'
             ELSE 'Late-In'
       END) AS Status

FROM tbl_attn_temp t1, tbl_assigned t3, tbl_instructor_info t4
JOIN (SELECT DISTINCT attnDate FROM tbl_attn_temp) t2
WHERE t1.attndate = t2.attnDate AND t1.TraineeID = t4.InstructorID
AND t1.attnDate='2016-01-13'
AND(CASE WHEN t4.Slot ='1' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '1') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '1') 
         WHEN t4.Slot ='2' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '2') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '2')
         WHEN t4.Slot ='3' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '3') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '3')
         WHEN t4.Slot ='4' THEN t1.attnTime BETWEEN(SELECT minLimit FROM tbl_threshold WHERE id = '4') AND (SELECT maxLimit FROM tbl_threshold WHERE id = '4')
    END)
GROUP BY t1.TraineeID, t2.attnDate

Answer 1

只需在这些联合语句中添加括号即可.它适用于我,例如:(选择...限制1)联合(选择...限制1)联合(选择...限制1)

联合所有括号也有效.

Answer 2

尝试使用关键字union all代替union

尝试：

select * from (query 1)
union all
(query 2)