连接数据库-stone

# -*- coding:utf-8 -*-

import pymysql

class mysql:
    def __init__(self, host, port, dbuser, dbpwd, dbname):
      self.host = host
      self.port = port
      self.dbuser = dbuser
      self.dbpwd = dbpwd
      self.dbname = dbname
      self._conn = None
      self.Connect()   # 默认链接数据库， 最后要调用关闭链接的函数Con_close()函数

    def Connect(self):
        if not self._conn:
            # print('\033[33m 已创建数据库链接.......... \033[5m')
            self._conn = pymysql.connect(host=self.host,
                                         port=self.port,
                                         user=self.dbuser,
                                         passwd=self.dbpwd,
                                         db=self.dbname,
                                         use_unicode=True,
                                         charset='utf8',
                                         cursorclass=pymysql.cursors.DictCursor)    # cursorclass=pymysql.cursors.DictCursor
                                         #  MySQLdb默认查询结果都是返回tuple，输出时候不是很方便，必须按照0，1这样读取，
                                         # 无意中在网上找到简单的修改方法，就是传递一个cursors.DictCursor就行。
        else:
            print('\033[33m 链接数据库已存在，请直接操作！\033[5m')
            pass

    def Con_close(self):
        if self._conn:
            # print('\033[33m 数据库链接已关闭！！！ \033[5m')
            self._conn.close()
            self._conn = None
            pass
        pass

    def NewCursor(self):
        cur = self._conn.cursor()
        if cur:
            return cur
        else:
            print('\033[33m #Error# Get New Cursor Failed \033[5m')
            return None
        pass

    def DelCursor(self, cur):
        if cur:
            cur.close()
            pass
        pass

    def Export(self, sql, file_name, colfg='\t\t'):
        """
        将查询结果导出到外部文件中
        :param sql:
        :param file_name:
        :param colfg:
        :return:
        """
        rt = self.Query(sql)
        if rt:
            with open(file_name, 'w') as fd:
                for row in rt:
                    in_info = ''
                    for col in row:
                        in_info += str(col) + colfg
                    in_info += '\n'
                    fd.write(in_info)

    def Query(self, sql, debug=0):
        """
        对数据库执行查询操作，sql为所需要执行的查询语句，debug控制是否显示查询的表结构（默认不查询即debug=0）
        :param sql:
        :param debug:
        :return:
        """
        rt = []
        cur = self.NewCursor()
        if not cur:
            return rt
        try:
            cur.execute(sql)
            while 1:
                ts = cur.fetchone()
                if ts is None:
                    break
                rt.append(ts)
            if debug:
                filename = []
                for field in cur.description:
                    filename.append(field[0])
                    print(filename)
                    # print('\033[33m Query Success!!! \033[5m')
        except Exception as err:
            print(err)
            print('\033[33m Exec Sql failed: "{0}" \033[5m'.format(sql))
        finally:
            self.DelCursor(cur)
            return rt

    def Exec(self, sql):
        """
        对数据库执行增、删、改操作，传入需要执行的SQL语句
        :param sql:
        :return:
        """
        rt = None
        cur = self.NewCursor()
        if not cur:
            return rt
        try:
            cur.execute(sql)
            # print('\033[33m update/delete/insert Success! \033[5m')
            self._conn.commit()
        except Exception as err:
            print('\033[33m Exec Sql Failed: "{0}" \033[5m'.format(sql))
            print(err)
            cur.rollback()
        finally:
            self.DelCursor(cur)
            return rt