How to find duplicate names in a table

Question

I have a table having person names address and job title. the names are repeating sometimes. I have to compare if two people have the same name and same address than i have to keep only 1 record of them.

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

Answer 1

To find the duplicates you can do:

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

To remove duplicates you could do:

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

To Insert in Person table you would do:

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)

Answer 2

SELECT P_Name,P_Address,count(*)
FROM Data_Excel
GROUP BY P_Name,P_Address
HAVING count(*) > 1;

This will give you the records with same P_Name & P_Address.