Question

我想获得SERIAL_NUM和EMP_NAME的不同值，但以下查询会引发错误。

SELECT SERIAL_NUM,EMP_NAME,NOTESID FROM DB2INST1.EMP_HC 
GROUP BY 
SERIAL_NUM,EMP_NAME,NOTESID 
HAVING   
FUNC_VP ='Bob '  AND 
VICE_PRES ='Bob'  AND 
DIRECTOR ='Michael'  AND 
THIRD_LINE ='Linda '

错误

DB2 SQL Error: SQLCODE=-119, SQLSTATE=42803, SQLERRMC=FUNC_VP, DRIVER=3.63.123

Answer 1

您不能在未出现在GROUP BY子句中的字段上使用HAVING，因为该字段可能在组中具有多个值。

您可能想要做的是使用plain WHERE过滤掉有趣的行，然后使用GROUP BY;

SELECT SERIAL_NUM,EMP_NAME,NOTESID 
FROM DB2INST1.EMP_HC 
WHERE FUNC_VP ='Bob '  
  AND VICE_PRES ='Bob'  
  AND DIRECTOR ='Michael'  
  AND THIRD_LINE ='Linda '  
GROUP BY SERIAL_NUM,EMP_NAME,NOTESID

...或者如果由于某种原因需要使用HAVING，您需要将字段FUNC_VP，VICE_PRES，DIRECTOR和THIRD_LINE添加到GROUP BY;

GROUP BY SERIAL_NUM,EMP_NAME,NOTESID,FUNC_VP,VICE_PRES,DIRECTOR,THIRD_LINE

Answer 2

如果您想要＆＃34; SERIAL_NUM和EMP_NAME的不同值＆＃34;如果notesid和serial_num有多种组合，您需要告诉数据库选择emp_name哪个。如果您不关心自己获得的notesid，您可以例如使用min()

SELECT serial_num,
       emp_name,
       min(notesid) as notesid
FROM db2inst1.emp_hc 
WHERE func_vp ='Bob '  
  AND vice_pres ='Bob'  
  AND director ='Michael'  
  AND third_line ='Linda'  
GROUP BY serial_num,emp_name

Db2选择查询与group by子句抛出错误？

2 个答案: