如何获得联接中相同行的总和

Question

I got a problem with my SQL code, I use multiple joins from different tables and my code looks like this:

SELECT Person.navn, Vare.varenavn, Ordre.antal FROM Ordre
JOIN Person
ON Person.Id = Ordre.P_id
JOIN Vare
ON Vare.Id = Ordre.vareid

My problem is that it turns out like this

I want it to remove duplicates and add the numbers together in the "antal" column so it should be: "Tulle - Banan - 9"

Thank you!

Edit:

I changed my datatypes from text to nvchar and varchar. I used @lad2025's top answer.

Answer 1

Looks like you need grouping and SUM aggregate function:

SELECT Person.navn, Vare.varenavn, SUM(Ordre.antal) AS antal
FROM Ordre
JOIN Person
  ON Person.Id = Ordre.P_id
JOIN Vare
  ON Vare.Id = Ordre.vareid
GROUP BY Person.navn, Vare.varenavn;

EDIT:

Do not use obsolete types text/ntext/image , for now you can use CAST but you should consider changing column datatype:

SELECT CAST(Person.navn AS NVARCHAR(MAX)),
       CAST(Vare.varenavn AS NVARCHAR(MAX)),
       SUM(Ordre.antal) AS antal
FROM Ordre
JOIN Person
  ON Person.Id = Ordre.P_id
JOIN Vare
  ON Vare.Id = Ordre.vareid
GROUP BY CAST(Person.navn AS NVARCHAR(MAX)), CAST(Vare.varenavn AS NVARCHAR(MAX));

ntext, text, and image :

ntext, text, and image data types will be removed in a future version of Microsoft SQL Server. Avoid using these data types in new development work, and plan to modify applications that currently use them. Use nvarchar(max), varchar(max), and varbinary(max) instead.