SQL合并的行相差1参数

Question

Okay, so I'm woking on a database, where I have basically a list of ownerships. And sometimes I receive almost duplicate rows, differing only in the amount of the property. I'd like to merge them into one, setting the amount as the sum of the two. Example:

Name  Surname Amount
Ann   Evans   4
Ann   Evans   7

And I'd like to have just:

Ann   Evans   11

How do I merge two rows having a common tuple?

Answer 1

Use SUM() aggregate function along with GROUP BY clause:

SELECT Name, 
       Surname, 
       SUM(Amount) AS total_amount
  FROM tbl 
GROUP BY 
       Name, 
       Surname;

UPD. Michał Szydłowski : Okay, but I don't want to select, I want to run an update query, that will permanently modify the table.

The best option I see here, is to use INSERT INTO ... SELECT :

CREATE TABLE temp_tbl LIKE tbl;

INSERT INTO temp_tbl (Name, Surname, Amount)
SELECT Name, 
       Surname, 
       SUM(Amount) 
  FROM tbl 
GROUP BY 
       Name, 
       Surname;

TRUNCATE tbl;

INSERT INTO tbl (Name, Surname, Amount)
SELECT Name, 
       Surname, 
       Amount
  FROM temp_tbl;

Answer 2

将聚合函数SUM（）与GROUP BY子句一起使用，按所需的列数和结果分组

select Name,Surname,sum(Amount) as Amount from table group by Name,Surname

Answer 3

Try this:

SELECT Name, SurName, SUM(Amount) as TotalAmount FROM myTable GROUP BY Name, SurName

Hope this help.