def create_constants(self, rdbms):
<EOL>if rdbms == '<STR_LIT>':<EOL><INDENT>module = locate('<STR_LIT>')<EOL>return module.MySqlConstants(self.output)<EOL><DEDENT>if rdbms == '<STR_LIT>':<EOL><INDENT>module = locate('<STR_LIT>')<EOL>return module.MsSqlConstants(self.output)<EOL><DEDENT>if rdbms == '<STR_LIT>':<EOL><INDENT>module = locate('<STR_LIT>')<EOL>return module.PgSqlConstants(self.output)<EOL><DEDENT>raise Exception("<STR_LIT>".format(rdbms))<EOL>
Factory for creating a Constants objects (i.e. objects for creating constants based on column widths, and auto
increment columns and labels).

:param str rdbms: The target RDBMS (i.e. mysql, mssql or pgsql).

:rtype: pystratum.Constants.Constants