sql - 如何在表中查找重复名称

Question

我有一张表，上面有人名地址和职位。
名字有时会重复。我必须比较两个人是否有相同的名字和相同的地址，而不是我只需要保留他们的 1 条记录。

Table: Data_Excel
Name: P_Name
Address: P_Address
City:  P_city

Answer 1

要查找重复项，您可以执行以下操作:

SELECT P_name,
  P_Address,
  P_city
FROM Data_Excel
GROUP BY P_Name,
  P_Address,
  P_city
HAVING COUNT(*) > 1;

要删除重复项，您可以执行以下操作:

DELETE
FROM Data_Excel
WHERE rowid NOT IN (
    SELECT MIN(rowid)
    FROM Data_Excel
    GROUP BY P_Name,
      P_Address,
      P_city
    );

要在 Person 表中插入，您可以执行以下操作:

INSERT INTO Person(id,name)
SELECT (SELECT MAX(id)+1 FROM Person),P_Name 
FROM Data_Excel WHERE P_Name NOT IN (SELECT name FROM Person)