Looping through int values in a stored procedure

You can definitely refactor this repetitive calculation using a loop. SQL Server does not have native arrays, but you can handle this by iterating over the variables using a WHILE loop. Here's how you can refactor the procedure using a loop:

 

DECLARE @i INT = 1;
DECLARE @sumA DECIMAL(12, 2) = 0;
DECLARE @sumV DECIMAL(12, 2) = 0;
DECLARE @currentResult DECIMAL(6, 2);

WHILE @i <= 12
BEGIN
    -- Accumulate sums
    SET @sumA = @sumA + CASE @i 
                          WHEN 1 THEN @a1
                          WHEN 2 THEN @a2
                          WHEN 3 THEN @a3
                          WHEN 4 THEN @a4
                          WHEN 5 THEN @a5
                          WHEN 6 THEN @a6
                          WHEN 7 THEN @a7
                          WHEN 8 THEN @a8
                          WHEN 9 THEN @a9
                          WHEN 10 THEN @a10
                          WHEN 11 THEN @a11
                          WHEN 12 THEN @a12
                        END;

    SET @sumV = @sumV + CASE @i 
                          WHEN 1 THEN @v1
                          WHEN 2 THEN @v2
                          WHEN 3 THEN @v3
                          WHEN 4 THEN @v4
                          WHEN 5 THEN @v5
                          WHEN 6 THEN @v6
                          WHEN 7 THEN @v7
                          WHEN 8 THEN @v8
                          WHEN 9 THEN @v9
                          WHEN 10 THEN @v10
                          WHEN 11 THEN @v11
                          WHEN 12 THEN @v12
                        END;

    -- Perform calculation and store the result
    SET @currentResult = CONVERT(DECIMAL(6,2), (@sumA * 200000) / @sumV);

    -- Dynamically assign the result to variables (based on the index)
    -- You could also store this in a temp table if dynamic assignment isn't needed
    IF @i = 1 SET @result1 = @currentResult;
    IF @i = 2 SET @result2 = @currentResult;
    IF @i = 3 SET @result3 = @currentResult;
    IF @i = 4 SET @result4 = @currentResult;
    IF @i = 5 SET @result5 = @currentResult;
    IF @i = 6 SET @result6 = @currentResult;
    IF @i = 7 SET @result7 = @currentResult;
    IF @i = 8 SET @result8 = @currentResult;
    IF @i = 9 SET @result9 = @currentResult;
    IF @i = 10 SET @result10 = @currentResult;
    IF @i = 11 SET @result11 = @currentResult;
    IF @i = 12 SET @result12 = @currentResult;

    -- Increment the loop
    SET @i = @i + 1;
END