SQL loop to generate random numbers

DECLARE @i INT

DECLARE @dian DECIMAL(7,2)

SET @i = 1

WHILE @i < 40

BEGIN

SET @dian = rand()*1000

INSERT INTO tbl_energy_electricity_hour_201701

     ([value])

     VALUES

     (CAST(@dian AS DECIMAL(7,2)))

SET @i = @i + 1

end

SQL loop to generate random numbers within 1000