Question

我有一个名为users的表，其中包含first name和last name，我希望保留一条同一first name和last name的记录，其他记录将被删除。

例如：

first name: Peter last name: White
first name: Mary last name: White
first name: John last name: Brown
first name: Peter last name: White

执行SQL后：

first name: Peter last name: White
first name: Mary last name: White
first name: John last name: Brown

Answer 1

SQL Server的一个很好的功能是能够使用CTE进行更新，插入和删除。这是一种方法：

with fordeletion as (
      select t.*,
             row_number() over (partition by fname, lname order by (select NULL)) as seqnum
      from t
     )
delete from fordeletion
    where seqnum > 1;

如何使用SQL删除重复的非唯一数据？

1 个答案: