Returns an object containing field information.
sybase_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by sybase_fetch_field() is retrieved.
The properties of the object are:
name - column name. if the column is a result of a function, this property is set to computed#N, where #N is a serial number.
column_source - the table from which the column was taken
max_length - maximum length of the column
numeric - 1 if the column is numeric
type - datatype of the column
See also sybase_field_seek().