Returns an associative array with fieldnames as key and
the SQL fieldproperties as data for a query with result_id. Returns FALSE on error.
Returns the Informix SQL fieldproperties of every field
in the query as an associative array. Properties are encoded
as: "SQLTYPE;length;precision;scale;ISNULLABLE" where SQLTYPE
= the Informix type like "SQLVCHAR" etc. and ISNULLABLE = "Y"
or "N".