Python之mysql数据库更新表数据接口实现

Posted 2020-10-15 哈哈丶Stupid

昨天，因为项目需求要添加表的更新接口，来存储预测模型训练的数据。

先码为敬~~~~~~~

  1 # -*- coding: utf-8 -*-
  2 import pymysql
  3 import settings
  4 
  5 class mysql(object):
  6     def __init__(self):
  7         self.db = None
  8 
  9     def connect(self):
 10 
 11           self.db = pymysql.connect(host=settings.ip, port=settings.port, user=settings.mysql_user, passwd=settings.mysql_passwd, db=settings.database, )
 12         #   print("connect is ok")
 13           # return 1
 14     def disconnect(self):
 15         self.db.close()
 16         # return -1
 17 
 18     def create_table(self, tablename, columns, spec=‘time‘):
 19         """
 20         :param tablename:
 21         :param spec:
 22         :param columns: 列表[]
 23         :return:
 24         """
 25 
 26         type_data = [‘int‘, ‘double(10,3)‘]
 27         cursor = self.db.cursor()
 28         sql="create table %s("%(tablename,)
 29         sqls=[]
 30         for col in columns:
 31             #判断是否time_num
 32             if col==spec:
 33                 sqls.append(‘%s %s primary key‘%(col,type_data[0]))
 34             else:
 35                 sqls.append(‘%s %s‘%(col,type_data[1]))
 36 
 37         sqlStr = ‘,‘.join(sqls)
 38         sql+=sqlStr+‘)‘
 39         try:
 40             cursor.execute(sql)
 41             print("Table %s is created"%tablename)
 42         except:
 43             self.db.rollback()
 44 
 45     def is_table_exist(self, tablename,dbname):
 46         cursor=self.db.cursor()
 47         sql="select table_name from information_schema.TABLES where table_schema=‘%s‘ and table_name = ‘%s‘"%(dbname,tablename)
 48         #results="error:Thie table is not exit"
 49         try:
 50             cursor.execute(sql)
 51 
 52             results = cursor.fetchall() #接受全部返回行
 53         except:
 54             #不存在这张表返回错误提示
 55              raise Exception(‘This table does not exist‘)
 56         if not results:
 57              return None
 58         else :
 59             return results
 60     # print datas
 61     def insert_mysql_with_json(self, tablename, datas):
 62         """
 63 
 64         :param tablename:
 65         :param datas:字典{(key: value),.....}
 66         :return:
 67         """
 68         # keys = datas[0]
 69         keys = datas[0].keys()
 70         keys = str(tuple(keys))
 71         keys = ‘‘.join(keys.split("‘")) # 用‘ 隔开
 72         print(keys)
 73         ret = []
 74         for dt in datas:
 75             values = dt.values()   ##      ‘str’ object has no attribute#
 76             sql = "insert into %s" % tablename + keys
 77             sql = sql + " values" + str(tuple(values))
 78             ret.append(sql)
 79             # print("1")
 80         # print keys  insert into %tablename dat[i]  values str[i]
 81 
 82         self.insert_into_sql(ret)
 83         print("1")
 84     def insert_into_sql(self,sqls):
 85         cursor = self.db.cursor()
 86         for sql in sqls:
 87             # 执行sql语句
 88             try:
 89                 cursor.execute(sql)
 90                 self.db.commit()
 91                 # print("insert %s" % sql, "success.")
 92             except:
 93                 # Rollback in case there is any error
 94                 self.db.rollback()
 95     #找列名
 96     def find_columns(self, tablename):
 97         sql = "select COLUMN_NAME from information_schema.columns where table_name=‘%s‘" % tablename
 98         cursor = self.db.cursor()
 99         try:
100             cursor.execute(sql)
101             results = cursor.fetchall()
102         except:
103             raise Exception(‘hello‘)
104         return tuple(map(lambda x: x[0], results))
105 
106     def find(self, tablename, start_time, end_time, fieldName=None):
107         """
108         :param tablename: test_scale1015
109         :param fieldName: None or (columns1010, columns1011, columns1012, columns1013, time)
110         :return:
111         """
112         cursor = self.db.cursor()
113         sql = ‘‘
114         if fieldName==None:
115             fieldName = self.find_columns(tablename)
116             sql = "select * from %s where time between %s and %s" % (tablename, str(start_time), str(end_time))
117             # print(‘None‘)
118         else:
119             fieldNameStr = ‘,‘.join(fieldName)
120             sql = "select %s from %s where time between  %s and %s" % (
121             fieldNameStr, tablename, str(start_time), str(end_time))
122             # print(‘sm‘)
123         try:
124             cursor.execute(sql)
125             results = cursor.fetchall()
126         except:
127             raise Exception(‘hello‘)
128         return fieldName, results,
129     
130     #样例 data = [{‘time‘:123321,‘predict‘:1.222},{‘time‘:123322,‘predict‘:1.223},{‘time‘:123324,‘predict‘:1.213}]
131     def updata(self,datas, tablename):
132         cursor = self.db.cursor()
133         columns = []
134         for data in datas:
135             for i in data.keys():
136                 columns.append(i)
137             # print(columns)
138             break
139             # columns_2=columns[:]
140         db.connect()
141         if db.is_table_exist(settings.tablename_2, settings.database):
142                 # exists
143                 # pass
144                 for col in columns:
145                     if col != ‘time‘:
146                         sql = "alter table %s add column %s double(10,3);" % (settings.tablename_2, col)
147                         try:
148                             cursor.execute(sql)
149                             print("%s is altered ok" % (col))
150                         except:
151                             print("alter is failed")
152                  
153 
154                 ret = []
155                 for i in datas:
156                     col = []
157                     for ii in i.keys():
158                         col.append(ii)
159                     #time = col[0]  and  predict = col[1]
160                     time_data = i[col[0]]
161                     predic_data = i[col[1]]
162                     sql = "update %s set %s=‘%s‘where %s=%s"%(settings.tablename_2,col[1],predic_data,col[0],time_data)
163                     ret.append(sql)
164                 self.insert_into_sql(ret)
165 
166                 # db.insert_mysql_with_json(tablename, datas)
167 
168 
169         else:
170                 # no exists
171                 db.create_table(settings.tablename_2, columns)
172                 db.insert_mysql_with_json(settings.tablename_2, datas)
173 
174 db = mysql()

View Code

其中update（）函数，是新添加的接口：

传入的data的样例 data = [{‘time‘:123321,‘predict‘:1.222},{‘time‘:123322,‘predict‘:1.223},{‘time‘:123324,‘predict‘:1.213}] 这样子的。

一个列表里有多个字典，每个字典有time和predict。如果需要存predict_2,predict_3的时候，则实现更新操作，否则，只进行创表和插入数据的操作~~~~~~

看起来是不是很简单~~~~~~

这个接口还没有进行优化等操作，很冗余~~~~

毕竟项目还在测试阶段，等先跑通了，在考虑优化吧~~~~~~

有不足之处，希望指正，共同进步~~~~~~~