Returns the absolute value of an expression.
abs(numeric_expression)
is a column, variable, or expression with datatype that is an exact numeric, approximate numeric, money, or any type that can be implicitly converted to one of these types.
Returns the absolute value of -1:
select abs(-1)
----------- 1
abs, a mathematical function, returns the absolute value of a given expression. Results are of the same type and have the same precision and scale as the numeric expression.
ANSI SQL – Compliance level: Transact-SQL extension.
Any user can execute abs.