Parse filename's contents and creates a #GdaBatch object which contains all the
#GdaStatement objects created while parsing (one object per SQL statement).
filename's contents are parsed and #GdaStatement objects are created as long as no error is found. If an error is found
at some point, then the parsing stops, error may be set and null is returned
if sql is null, then the returned #GdaBatch object will contain no statement.
Parse filename's contents and creates a #GdaBatch object which contains all the #GdaStatement objects created while parsing (one object per SQL statement).
filename's contents are parsed and #GdaStatement objects are created as long as no error is found. If an error is found at some point, then the parsing stops, error may be set and null is returned
if sql is null, then the returned #GdaBatch object will contain no statement.