Getting wrong data from relation - sql

Question

I have 2 tables:
DesignGroup table:
+--------------------------------------+--------+
| DesignGroupId | Name |
+--------------------------------------+--------+
| 9D32C543-24EA-497E-918E-387C8A66BF1A | Group1 |
| 532C543E-24EA-497E-918E-387C8A66BF1A | Group2 |
+--------------------------------------+--------+
Design table:
+-----------+---------------+--------------------------------------+
| DesignKey | Name | DesignGroupId |
+-----------+---------------+--------------------------------------+
| 1 | Design | 9D32C543-24EA-497E-918E-387C8A66BF1A |
| 2 | Design | 9D32C543-24EA-497E-918E-387C8A66BF1A |
| 3 | AnotherDesign | 532C543E-24EA-497E-918E-387C8A66BF1A |
+-----------+---------------+--------------------------------------+
As you can see multiple designs can have same DesignGroupId, So I make a query like:
DECLARE #DesignName VARCHAR(255) = 'Design'
SELECT
[D].[Name] AS [Display],
[D].[DesignKey] AS [Value]
FROM
[Design] AS [D]
JOIN
[DesignGroup] AS [DG] ON [D].[DesignGroupId] = [DG].[DesignGroupId]
GROUP BY
[D].[Name], [D].[DesignKey];
My desire result of this, is get only one value one [Display] and one [Value] of each DesignGroupId, so my desire result there was:
+---------------+-------+
| Display | Value |
+---------------+-------+
| Design | 1 |
| AnotherDesign | 3 |
+---------------+-------+
But I'm getting result foreach DesignKey like:
+---------------+-------+
| Display | Value |
+---------------+-------+
| Design | 1 |
| Design | 2 |
| AnotherDesign | 3 |
+---------------+-------+
How can I solve this? Regards

Answer 1

I don't see why you need to join the tables.
The results you want depend only on the data from the table [Design].
So GROUP BY [Name] and get the minimum value of [DesignKey]:
SELECT
[Name] AS [Display],
MIN([DesignKey]) AS [Value]
FROM [Design]
GROUP BY [Name];
But this will be fine if the table has only one value for DesignGroupId.
What do you need as a result for the other DesignGroupIds?
Maybe GROUP BY [DesignGroupId], [Name]:
SELECT
[DesignGroupId],
[Name] AS [Display],
MIN([DesignKey]) AS [Value]
FROM [Design]
GROUP BY [DesignGroupId], [Name];

Answer 2

Is your objective to get the minimum DesignKey value for each Name (Display) and Group? You can wrap your result into a minimum value outer query:
SELECT DISPLAY, MIN(VALUE) from (
SELECT
[D].[Name] AS [Display],
[D].[DesignKey] AS [Value]
FROM
[Design] AS [D]
JOIN
[DesignGroup] AS [DG] ON [D].[DesignGroupId] = [DG].[DesignGroupId]
GROUP BY
[D].[Name], [D].[DesignKey])
GROUP BY Display;