CREATE TRIGGER [dbo].[Trigger_Customer]
ON [dbo].[Customer]
AFTER INSERT
AS
BEGIN
    SET NOCOUNT ON;

    DECLARE @UserInput1 VARCHAR(50);
    DECLARE @Counter BIGINT;

    SELECT @UserInput1 = UserInput1 FROM inserted;

    -- Check if the combination of UserInput1 already exists
    IF EXISTS (
        SELECT 1
        FROM [dbo].[Customer]
        WHERE UserInput1 = @UserInput1
    )
    BEGIN
        -- Retrieve the current maximum Counter value for the combination
        SELECT @Counter = MAX([Counter])
        FROM [dbo].[Customer]
        WHERE UserInput1 = @UserInput1;
    END
    ELSE
    BEGIN
        -- Combination does not exist, start Counter from the beginning
        SET @Counter = 100000;
    END

    -- Increment the Counter for the combination
    UPDATE [dbo].[Customer]
    SET [Counter] = @Counter +1
    WHERE UserInput1 = @UserInput1 AND [RunningNo] IN (SELECT [RunningNo] FROM inserted);

    -- Update the inserted rows with the concatenated ID
    UPDATE rh
    SET ID = CONCAT(@UserInput1, '-', rh.[Counter])
    FROM [dbo].[Customer] rh
    INNER JOIN inserted i ON rh.RunningNo = i.RunningNo;
END