ATN2 (Transact-SQL)
SQL Server 2012
Returns the angle, in radians, between the positive x-axis and the ray from the origin to the point (y, x), where x and y are the values of the two specified float expressions.
Returns the angle, in radians, between the positive x-axis and the ray from the origin to the point (y, x), where x and y are the values of the two specified float expressions.