SMALLINT abs(TINYINT x)
INT abs(SMALLINT x)
BIGINT abs(INT x)
LARGEINT abs(BIGINT x)
LARGEINT abs(LARGEINT x)
DOUBLE abs(DOUBLE x)
FLOAT abs(FLOAT x)
DECIMAL abs(DECIMAL x)` 

mysql> select abs(-2);
+---------+
| abs(-2) |
+---------+
|       2 |
+---------+
mysql> select abs(3.254655654);
+------------------+
| abs(3.254655654) |
+------------------+
|      3.254655654 |
+------------------+
mysql> select abs(-3254654236547654354654767);
+---------------------------------+
| abs(-3254654236547654354654767) |
+---------------------------------+
| 3254654236547654354654767       |
+---------------------------------+

ABS