Question

我们如何从列值中检索信息作为行信息？例如，我们有一个表

|-----------|-------------|--------------|
|      ID   |     Field   |  FieldVlaue  |
|-----------|-------------|--------------|
|      1    |     Name    |  Jack        |
|-----------|-------------|--------------|
|      1    |     Country |  Australia   |
|-----------|-------------|--------------|
|      1    |     PostCode|  0277        |
|-----------|-------------|--------------|
|      2    |     Name    |  John        |
|-----------|-------------|--------------|
|      2    |     address |  Wyard       |
|-----------|-------------|--------------|
|      2    |  ContactNum |  1234567     |
|-----------|-------------|--------------|

基于上表，我们如何获得像下面的表

|-----------|-------------|--------------|-------------|---------|-----------|
|      ID   |     Name    |  Country     | PostCode    |Address  | ContactNum|
|-----------|-------------|--------------|-------------|---------|-----------|
|      1    |     Jack    |  Australia   | 0277        |Null     | Null      |
|-----------|-------------|--------------|-------------|---------|-----------|
|      2    |     John    |  Null        | Null        | Wyard   |1234567
|-----------|-------------|--------------|-------------|---------|-----------|

Answer 1

使用条件汇总

select id,
       max(case when Field='Name' then FieldVlaue end) as Name,
       max(case when Field='Country' then FieldVlaue end) as Country,
       max(case when Field='PostCode' then FieldVlaue end) as PostCode,
       max(case when Field='Address' then FieldVlaue end ) as Address,
       max(case when Field='ContactNum' then FieldVlaue end) as ContactNum 
from t
group by id

如何检索列值作为行值？

1 个答案: