Question

以下是我的情景：

我有一个包含字段的表：

.constant

有2 PolicyID MemberType MemberAddress MemberCity个分类：

MemberType

只有MemberType ---------- Owners Dependents与地址和城市相关联。因此，当我有一个所有者和几个家庭成员（家属）时，只有所有者行显示一个地址，所以家属行地址字段显示Owners（旁注：所有者和同一家庭的所有者将具有相同的{{ 1}}）。如何填充地址字段，以便在有NULL地址字段的依赖项时，它将获取其所有者的地址并填充该字段。

当前结果

policyid

期望的结果

NULL

提前谢谢！

Answer 1

UPDATE t
SET t.MemberAddress = t2.MemberAddress and t.MemberCity=t2.MemberCity
FROM Table1 t 
INNER JOIN Table1 t2 ON t.Id = t2.Id 
WHERE t2.PolicyID = t.PolicyID AND t.MemberType<>'Owner' AND t.MemberAddress IS NULL

在运行更新检查之前，确保您正在更新正确的数据：

SELECT t.PolicyID, t2.PolicyID, t.MemberType, t2.MemberType, t.MemberAddress, t2.MemberAddress, t.MemberCity, t2.MemberCity
FROM Table1 t 
INNER JOIN Table1 t2 ON t.Id = t2.Id 
WHERE t2.PolicyID = t.PolicyID AND t.MemberType='Dependents' AND t.MemberAddress IS NULL

Answer 2

您可以在update语句中进行简单的加入，如下所示：

UPDATE p1
  SET p1.MemberAddress = p2.MemberAddress,
      p1.MemberCity = p2.MemberCity
FROM policy p1
INNER JOIN policy p2 ON p1.PolicyID = p2.PolicyID
    AND p2.MemberType = 'Owner'
WHERE p1.MemberType <> 'Owner';

select * from policy;  --change it to match your tablename

SQL Fiddle Demo

SQL如何填充NULL值

2 个答案: