SQL使用IIF填充空白

我有两列和几个类似的数据

sms_type        ID              fullname
incoming        2036037         NULL
outgoing        2036037         Jason Sayre

如果ID列匹配，我喜欢用相同的名称（Jason Sayre）填充NULL in fullname列
谢谢。

您可以使用

coalesce（）

和窗口函数：

select t.*,
       coalesce(fullname, max(fullname) over (partition by id)) as imputed_fullname
from t;

---

您可以尝试以下内部联接查询

create table MyTable(sms_type varchar(20)
, ID float
, fullname varchar(50))

insert into MyTable values
('incoming', 2036037, NULL),
('outgoing', 2036037, 'Jason Sayre')


SELECT MyTable.sms_type
 ,MyTable.ID
 ,ISNULL(MyTable.fullName, tblname.fullName) AS Name
FROM (
    SELECT ID
        ,max(fullname) AS fullName
    FROM MyTable
    GROUP BY ID
    ) tblname
INNER JOIN MyTable ON MyTable.ID = tblName.ID

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如果你碰巧在寻找更新，那么戈登的答案有点扭曲（+1）

示例

;with cte as (
Select *
      ,NewValue =max(fullname) over (partition by ID) 
 From YourTable
)
Update cte Set FullName=NewValue
  Where FullName is null   -- Where is optional

sms_type    ID      fullname
incoming    2036037 Jason Sayre
outgoing    2036037 Jason Sayre

更新后的表格

;with cte as (
Select *
      ,NewValue =max(fullname) over (partition by ID) 
 From YourTable
)
Update cte Set FullName=NewValue
  Where FullName is null   -- Where is optional

sms_type    ID      fullname
incoming    2036037 Jason Sayre
outgoing    2036037 Jason Sayre

---

出现错误“关键字“over”附近的语法不正确”。@Tsang不应该出现错误。请勾选“警告：通过聚合或其他集合操作消除空值”