抽象化对SQL语句的操作

[LeoQuote]

目前涉及到SQL语句的操作, 都是函数, 可以把这些操作抽象成一个个的 Engine

相当于 java 里的 Interface , 然后再继承这个Interface , 实现一个 MysqlEngine , 这样方便其它数据库比如 PG , oracle等的接入

class EngineBase:
    def __init__(self, instance=None, workflow=None):
        self.instance = instance
        self.workflow = workflow
    @property
    def Connection(self):
        """返回一个conn实例"""
        pass
    def get_all_databases(self):
        """获取数据库列表, 返回一个list"""
        pass
    def get_all_tables(self, db_name):
        """获取table 列表, 返回一个list"""
        pass
    def get_all_columns_by_tb(self, db_name, table_name):
        """获取所有字段, 返回一个列表"""
        pass
    def query_check(self, db_name, sqlcontent):
        """查询语句的检查"""
        pass
    def query(self, db_name, sqlcontent):
        """实际查询"""
        pass
    def execute_check(self, db_name, sqlcontent):
        """执行语句的检查"""
        pass
    def execute(self, db_name, sqlcontent):
        """执行语句"""
        pass

统一了interface之后, 只要继承interface , 统一返回对象, 实现出来的对象就一定能适配到系统中.

比如有 查询方法叫 Query , 那么代码里只要 get_engine , 然后 SomeEngine.query ,就一定能得到预期的结果.

适配数据库时, 也就不需要更改主逻辑部分的代码. 更棒的是, 如果你不用这个引擎, 就不会import到那些库, 那么在你不用pg的时候, 不装pg相关的依赖也是可以的. 测试功能会更加简单, 尤其在一些依赖很难装的windows 机器上.

[hhyo]

帮忙改造一下，顺便让也学习一下~

[LeoQuote]

审核结果的定义

class EngineResult:
    def __init__(self, inception_result=[], **kwargs):
        if inception_result:
            column_list = ['ID', 'stage', 'errlevel', 'stagestatus', 'errormessage', 'SQL', 'Affected_rows', 'sequence',
                   'backup_dbname', 'execute_time', 'sqlsha1']
            self.id = inception_result[0]
            self.stage = inception_result[1]
            self.errlevel = inception_result[2]
            self.stagestatus = inception_result[3]
            self.errormessage = inception_result[4]
            self.sql = inception_result[5]
            self.affected_rows = inception_result[6]
            self.sequence = inception_result[7]
            self.backup_dbname = inception_result[8]
            self.execute_time = inception_result[9]
            self.sqlsha1 = inception_result[10]
        self.id = kwargs['id']
        self.stage = kwargs['stage']
        self.errlevel = kwargs['errlevel']
        self.stagestatus = kwargs['stagestatus']
        self.errormessage = kwargs['errormessage']
        self.sql = kwargs['sql']
        self.affected_rows = kwargs['affected_rows']
        self.sequence = kwargs['sequence']
        self.backup_dbname = kwargs['backup_dbname']
        self.execute_time = kwargs['execute_time']
        self.sqlsha1 = kwargs['sqlsha1']

审核结果集的定义

class ResultSet:
    def __init__(self, query='', resultset = [], status=None,**kwargs):
        self.query = query
        self.resultset = []
        self.status = status
    def __repr__(self):
        for i in self.resultset:
            yield i