   DOUBLE[(M,D)] [UNSIGNED] [ZEROFILL]

A normal-size (double-precision) floating-point number.
Allowable values are -1.7976931348623157E+308 to
-2.2250738585072014E-308, 0, and
2.2250738585072014E-308 to 1.7976931348623157E+308.  If
UNSIGNED is specified, negative values are disallowed.
M is the display width and D is the number of decimals.
DOUBLE without arguments or FLOAT(p) (where
p is in the
range from 25 to 53) stands for a double-precision floating-point number.

   DOUBLE PRECISION[(M,D)] [UNSIGNED] [ZEROFILL]
   REAL[(M,D)] [UNSIGNED] [ZEROFILL]

These are synonyms for DOUBLE.
Exception: If the server SQL mode includes the REAL_AS_FLOAT option,
REAL is a synonym for FLOAT rather than DOUBLE.
