base.py 文件源码

def get_column_specification(self, column, **kw):
        """Builds column DDL."""

        colspec = [
            self.preparer.format_column(column),
            self.dialect.type_compiler.process(
                column.type, type_expression=column)
        ]

        is_timestamp = isinstance(column.type, sqltypes.TIMESTAMP)

        if not column.nullable:
            colspec.append('NOT NULL')

        # see: http://docs.sqlalchemy.org/en/latest/dialects/
        #   mysql.html#mysql_timestamp_null
        elif column.nullable and is_timestamp:
            colspec.append('NULL')

        default = self.get_column_default_string(column)
        if default is not None:
            colspec.append('DEFAULT ' + default)

        if column.table is not None \
            and column is column.table._autoincrement_column and \
                column.server_default is None:
            colspec.append('AUTO_INCREMENT')

        return ' '.join(colspec)