How to insert multiple rows into a table based on a range of numbers

Question

I have to insert a specific number of rows into a SQL Server table.

DECLARE @val AS INT = 20, 
        @val2 AS VARCHAR(50), 
        @Date AS DATETIME = CONVER         


        

Answer 1

You could use a recursive CTE.

DECLARE @i INT = 1
    , @m INT = 19
    , @d DATETIME2 = '2016-05-02';

WITH i AS (
    SELECT 0 AS increment
    UNION ALL
    SELECT i.increment + @i
    FROM i
    WHERE i.increment < @m
)
SELECT i.increment
    , DATEADD(DAY, i.increment, @d)
FROM i
OPTION (MAXRECURSION 100);

Note the OPTION (MAXRECUSION 100) hint at the bottom, which is not strictly necessary but I have included it to illustrate how it works. By default, there is a limit of 100 results using this method, so without this statement and if @m were a large number e.g. 1000 then SQL would generate an error. You can set the lmit to 0 which means unbounded, but only do this after testing your code, because it can get stuck in an infinite loop this way (which is why the limit exists by default).