group user assignment apis

src/Sql/dbo/Stored Procedures/GroupUser_UpdateGroups.sql

@@ -0,0 +1,44 @@
+CREATE PROCEDURE [dbo].[GroupUser_UpdateGroups]
+    @OrganizationUserId UNIQUEIDENTIFIER,
+    @GroupIds AS [dbo].[GuidIdArray] READONLY
+AS
+BEGIN
+    SET NOCOUNT ON
+
+    DECLARE @OrgId UNIQUEIDENTIFIER = (
+        SELECT TOP 1
+            [OrganizationId]
+        FROM
+            [dbo].[OrganizationUser]
+        WHERE
+            [Id] = @OrganizationUserId
+    )
+
+    ;WITH [AvailableGroupsCTE] AS(
+        SELECT
+            [Id]
+        FROM
+            [dbo].[Group]
+        WHERE
+            [OrganizationId] = @OrgId
+    )
+    MERGE
+        [dbo].[GroupUser] AS [Target]
+    USING 
+        @GroupIds AS [Source]
+    ON
+        [Target].[GroupId] = [Source].[Id]
+        AND [Target].[OrganizationUserId] = @OrganizationUserId
+    WHEN NOT MATCHED BY TARGET
+    AND [Source].[Id] IN (SELECT [Id] FROM [AvailableGroupsCTE]) THEN
+        INSERT VALUES
+        (
+            [Source].[Id],
+            @OrganizationUserId
+        )
+    WHEN NOT MATCHED BY SOURCE
+    AND [Target].[OrganizationUserId] = @OrganizationUserId
+    AND [Target].[GroupId] IN (SELECT [Id] FROM [AvailableGroupsCTE]) THEN
+        DELETE
+    ;
+END