自己写的postgreSQL查询语句

import psycopg2


class PostgreConn():
    '''
    数据库连接类
    '''
    def __init__(self, database, user, password, host, port):
        self.conn = psycopg2.connect(database=database, user=user, password=password, host=host, port=port)
        print('数据库连接成功')
        self.cur = self.conn.cursor()
        self.rows = None

    def cur(self):
        return self.cur()

    def execute(self, sql, fetchone=0):
        self.cur.execute(sql)
        if fetchone:
            self.rows = self.cur.fetchone()
        else:
            self.rows = self.cur.fetchall()
        return self.rows

    def close(self):
        self.cur.close()
        self.conn.close()
        print('数据库连接关闭')


def select_sql(table, keys, conditions, isdistinct=0):
    '''
        生成select的sql语句
    @table，查询记录的表名
    @key，需要查询的字段
    @conditions,插入的数据，字典
    @isdistinct,查询的数据是否不重复
    '''
    if isdistinct:
        sql = 'SELECT distinct %s ' % ",".join(keys)
    else:
        sql = 'SELECT  %s ' % ",".join(keys)
    sql += ' from %s ' % table
    if conditions:
        sql += ' WHERE %s ' % dict_str_and(conditions)
    return sql


def dict_str_and(dictin):
    '''
    将字典变成，key='value' and key='value'的形式
    '''
    tmplist = []
    for k, v in dictin.items():
        tmp = "%s='%s'" % (str(k), str(v))
        tmplist.append(' ' + tmp + ' ')
    return ' and '.join(tmplist)


def fSqlResult(r,key_list):
    '''
    :param r: 数据库fetchall的结果
    :param key_list: 查询字段的keys
    :return:
    format SQL Result 格式化数据库查询的结果，转化成包含多个字典的列表格式，即((1,2),(3,4))->[{"key1":1,"key2":2},{"key1":3,"key2":4}]
    返回 @dict 查询结果
    '''
    mlist=[]
    l=len(key_list)
    if r:
        for item in r:
            tmp={}
            for i in range(l):
                tmp[key_list[i]]=str(item[i])
            mlist.append(tmp)
    return mlist


conn = PostgreConn('settle', 'admin', 'settle8', '123.57.285.89', '5432')
key_list = ['user_id']
sql = select_sql('st_user', key_list, {'phone': '138****'})
print(sql)
r = conn.execute(sql)
re = fSqlResult(r, key_list)
print(re)
conn.close()