entity_relationship_diagram.py 文件源码

def lexical_analysis(self, src):
        delimited = re.sub(r'\s+', ' ', ' '.join(src.strip().split('\n'))).split(';')
        result = []
        for stmt in delimited:
            if stmt == '':
                return result
            string = pp.Regex('[a-zA-Z0-9=_]+')
            nums = pp.Regex('[0-9]+')
            ws = pp.OneOrMore(pp.White()).suppress()
            lp = pp.Regex('[(]').suppress()
            rp = pp.Regex('[)]').suppress()
            c = pp.Regex('[,]').suppress()
            q = pp.Regex("[']").suppress()

            table_name = string.setResultsName('table_name')
            create_table = (pp.Keyword('CREATE', caseless = True) + ws + pp.Keyword('TABLE', caseless = True) + ws + pp.Optional(pp.Keyword('IF', caseless = True) + ws + pp.Keyword('NOT', caseless = True) + ws + pp.Keyword('EXISTS', caseless = True))).suppress() + table_name + lp 

            column_name = string.setResultsName('column_name')
            data_type = string.setResultsName('data_type')
            length = lp + nums.setResultsName('length') + rp
            nullable = (pp.Optional(pp.Keyword('NOT', caseless = True) + ws) + pp.Keyword('NULL', caseless = True)).setResultsName('nullable')
            default_value = pp.Keyword('DEFAULT', caseless = True).suppress() + ws + string.setResultsName('default_value')
            auto_increment = pp.Keyword('AUTO_INCREMENT', caseless = True).setResultsName('auto_increment')
            column = pp.Optional(ws) + column_name + ws + data_type + pp.Optional(pp.MatchFirst([length, ws + nullable, ws + default_value, ws + auto_increment])) + pp.Optional(pp.MatchFirst([ws + nullable, ws + default_value, ws + auto_increment])) + pp.Optional(pp.MatchFirst([ws + default_value, ws + auto_increment])) + pp.Optional(ws + auto_increment) + pp.Optional(ws) + c

            primary_key = pp.Keyword('PRIMARY KEY', caseless = True).suppress() + lp + pp.OneOrMore(q + string.setResultsName('primary_key') + q + pp.Optional(c)) + rp + pp.Optional(c)
            key = pp.Keyword('KEY', caseless = True).suppress() + lp + q + string.setResultsName('key') + q + pp.Optional(c) + rp + pp.Optional(c)

            parser = create_table + pp.OneOrMore(pp.Group(column)) + pp.Optional(primary_key) + pp.Optional(key) + rp + pp.OneOrMore(ws + string).suppress()
            result.append(parser.parseString(stmt, parseAll=True))
        return result