Convert negative data into positive data in SQL Server

Solution 1:

You are thinking in the function ABS, that gives you the absolute value of numeric data.

SELECT ABS(a) AS AbsoluteA, ABS(b) AS AbsoluteB
FROM YourTable

Solution 2:

The best solution is: from positive to negative or from negative to positive

For negative:

SELECT ABS(a) * -1 AS AbsoluteA, ABS(b) * -1 AS AbsoluteB
FROM YourTable

For positive:

SELECT ABS(a) AS AbsoluteA, ABS(b)  AS AbsoluteB
FROM YourTable

Solution 3:

UPDATE mytbl
SET a = ABS(a)
where a < 0

Solution 4:

Use the absolute value function ABS. The syntax is

ABS ( numeric_expression )

Solution 5:

An easy and straightforward solution using the CASE function:

SELECT CASE WHEN ( a > 0 ) THEN (a*-1) ELSE (a*-1) END AS NegativeA,
       CASE WHEN ( b > 0 ) THEN (b*-1) ELSE (b*-1) END AS PositiveB
FROM YourTableName