cx_oracle.py 文件源码

def on_connect(self):
        if self.cx_oracle_ver < (5,):
            # no output type handlers before version 5
            return

        cx_Oracle = self.dbapi

        def output_type_handler(cursor, name, defaultType,
                                    size, precision, scale):
            # convert all NUMBER with precision + positive scale to Decimal
            # this almost allows "native decimal" mode.
            if self.supports_native_decimal and \
                    defaultType == cx_Oracle.NUMBER and \
                    precision and scale > 0:
                return cursor.var(
                            cx_Oracle.STRING,
                            255,
                            outconverter=self._to_decimal,
                            arraysize=cursor.arraysize)
            # if NUMBER with zero precision and 0 or neg scale, this appears
            # to indicate "ambiguous".  Use a slower converter that will
            # make a decision based on each value received - the type
            # may change from row to row (!).   This kills
            # off "native decimal" mode, handlers still needed.
            elif self.supports_native_decimal and \
                    defaultType == cx_Oracle.NUMBER \
                    and not precision and scale <= 0:
                return cursor.var(
                            cx_Oracle.STRING,
                            255,
                            outconverter=self._detect_decimal,
                            arraysize=cursor.arraysize)
            # allow all strings to come back natively as Unicode
            elif defaultType in (cx_Oracle.STRING, cx_Oracle.FIXED_CHAR):
                return cursor.var(unicode, size, cursor.arraysize)

        def on_connect(conn):
            conn.outputtypehandler = output_type_handler

        return on_connect