How to implement poor-man's version control with TSQL queries

Question

I have a table called Project. Each row completely describes a project and has a username, project name, project description and other numeric parameters that contain all the data about the project.
When multiple rows have the same username, this means a user owns multiple projects.
Now I want to implement a poor-man's version control for my users by adding a new integer column called version. When a user wants to save a new version of his project, the version is incremented and a new row is inserted into the table.
Some projects will have 1 version, others will have a dozen or more.
By default, the user should see a data grid of projects where only the latest version of the project is displayed (including the version count) and all the older versions of each project are ignored.
How do I write a TSQL query to populate this data grid (and ignore every version except the latest versions of each project)?
Thanks
Siegfried
siegfried heintze

Answer 1

Should this work? It prints all the rows.
DECLARE @Projects TABLE
([id] int IDENTITY(1,1), [Project] varchar(1), [Version] int)
INSERT INTO @Projects
([Project], [Version])
VALUES
('A', 1),
('A', 2),
('A', 3),
('A', 4),
('B', 1),
('B', 2),
('B', 3),
('C', 1),
('C', 2),
('D', 1)
-- DECLARE @User varchar(100)
SELECT *
FROM @Projects p
WHERE
-- UserName = @User AND
NOT EXISTS (SELECT 1
FROM @Projects q
WHERE q.id = p.id
AND q.Version < p.Version)
siegfried heintze
Nope you have condition wrong
In my suggestion i've used > and you replaced it with <
it should be this
SELECT *
FROM @Projects p
WHERE
NOT EXISTS (SELECT 1
FROM @Projects q
WHERE q.project= p.projects
AND q.Version > p.Version)
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