Question

我有这两个表，我将使用EMP_PHONE_ID加入以获得结果。 JOIN条件多一点很复杂，但这只是一个入门的样本。当我加入两个表时，我为每个EMP_ID获得了2行因为每个EMP_ID映射到两个EMP_PHONE_ID。我希望最终结果是单行结合PERM和TEMP值。

TABLE B 

EMP_PHONE_ID      ||    PERM_VALUE   ||    TEMP_VALUE
1                 ||      value1     ||      NULL 
2                 ||      NULL       ||      value2 
3                 ||      value3     ||      NULL 
4                 ||      NULL       ||      value4 


TABLE A

EMP_ID     ||EMP_PHONE_ID ||CODE
1          ||1            ||1    
1          ||2            ||2   
2          ||3            ||1    
2          ||4            ||2            




DESIRED RESULTS 

EMP_ID      ||    PERM_VALUE   ||    TEMP_VAL
1           ||      value1     ||      value2 
2           ||      value3     ||      value4 

Here's my select 
     SELECT
     CASE WHEN A.CODE = 1 THEN B.PERM_VALUE  END AS PERM_VALUE1,
     ASE WHEN A.CODE = 2 THEN B.PERM_VALUE  END AS PERM_VALUE2
     FROM TABLE A A,  TABLE B B
     WHERE A.EMP_PHONE_ID = B.EMP_PHONE_ID;



DESIRED RESULTS 

EMP_ID      ||    PERM_VALUE   ||    TEMP_VAL
1           ||      value1     ||      value2 
2           ||      value3     ||      value4

Answer 1

Inner join + Group By + Min or Max汇总应该适合您

SELECT EMP_ID,
       Min(PERM_VALUE) as PERM_VALUE,
       Min(TEMP_VALUE) as TEMP_VALUE
FROM   TABLEA A
       JOIN TABLEB B
         ON A.EMP_PHONE_ID = B.EMP_PHONE_ID
GROUP  BY EMP_ID

如果您想根据Code显示数据，请使用此

SELECT EMP_ID,
       Min(CASE WHEN A.CODE = 1 then PERM_VALUE end) as PERM_VALUE,
       Min(CASE WHEN A.CODE = 2 then TEMP_VALUE end) as TEMP_VALUE
FROM   TABLEA A
       JOIN TABLEB B
         ON A.EMP_PHONE_ID = B.EMP_PHONE_ID
GROUP  BY EMP_ID

我认为您在TABLEA

中以错误的方式存储数据

在SELECT语句中将多行组合成单行

1 个答案: