本文实例讲述了Python带动态参数功能的sqlite工具类。分享给大家供大家参考，具体如下：
最近在弄sqlite和python
在网上参考各教程后，结合以往java jdbc数据库工具类写出以下python连接sqlite的工具类
写得比较繁琐 主要是想保留一种类似java的Object…args动态参数写法 并兼容数组/list方式传递不定个数参数 并且返回值是List形式 dict字典 以便和JSON格式互相转换
在python中有一些区别 经过该工具类封装之后可以有以下用法：
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db.executeQuery("s * f t w id=? and name=?", "id01", "name01");//动态参数形式db.executeQuery("s * f t w id=? and name=?", ("id01", "name01"));//tuple元组式 等价上面 括号可省略db.executeQuery("s * f t w id=? and name=?", ["id01", "name01"]);//list数组形式 |
完整Python代码如下：
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#!/usr/bin/python#-*- coding:utf-8 -*- import sqlite3import os ## 连接数据库帮助类# eg:# db = database()# count,listRes = db.executeQueryPage("select * from student where id=? and name like ? ", 2, 10, "id01", "%name%")# listRes = db.executeQuery("select * from student where id=? and name like ? ", "id01", "%name%")# db.execute("delete from student where id=? ", "id01")# count = db.getCount("select * from student ")# db.close()#class database : dbfile = "sqlite.db" memory = ":memory:" conn = None showsql = True def __init__(self): self.conn = self.getConn() #输出工具 def out(self, outStr, *args): if(self.showsql): for var in args: if(var): outStr = outStr + ", " + str(var) print("db. " + outStr) return #获取连接 def getConn(self): if(self.conn is None): conn = sqlite3.connect(self.dbfile) if(conn is None): conn = sqlite3.connect(self.memory) if(conn is None): print("dbfile : " + self.dbfile + " is not found && the memory connect error ! ") else: conn.row_factory = self.dict_factory #字典解决方案 self.conn = conn self.out("db init conn ok ! ") else: conn = self.conn return conn #字典解决方案 def dict_factory(self, cursor, row): d = {} for idx, col in enumerate(cursor.description): d[col[0]] = row[idx] return d #关闭连接 def close(self, conn=None): res = 2 if(not conn is None): conn.close() res = res - 1 if(not self.conn is None): self.conn.close() res = res - 1 self.out("db close res : " + str(res)) return res #加工参数tuple or list 获取合理参数list #把动态参数集合tuple转为list 并把单独的传递动态参数list从tuple中取出作为参数 def turnArray(self, args): #args (1, 2, 3) 直接调用型 exe("select x x", 1, 2, 3) #return [1, 2, 3] <- list(args) #args ([1, 2, 3], ) list传入型 exe("select x x",[ 1, 2, 3]) len(args)=1 && type(args[0])=list #return [1, 2, 3] if(args and len(args) == 1 and (type(args[0]) is list) ): res = args[0] else: res = list(args) return res #分页查询 查询page页 每页num条 返回 分页前总条数 和 当前页的数据列表 count,listR = db.executeQueryPage("select x x",1,10,(args)) def executeQueryPage(self, sql, page, num, *args): args = self.turnArray(args) count = self.getCount(sql, args) pageSql = "select * from ( " + sql + " ) limit 5 offset 0 " #args.append(num) #args.append(int(num) * (int(page) - 1) ) self.out(pageSql, args) conn = self.getConn() cursor = conn.cursor() listRes = cursor.execute(sql, args).fetchall() return (count, listRes) #查询列表array[map] eg: [{'id': u'id02', 'birth': u'birth01', 'name': u'name02'}, {'id': u'id03', 'birth': u'birth01', 'name': u'name03'}] def executeQuery(self, sql, *args): args = self.turnArray(args) self.out(sql, args) conn = self.getConn() cursor = conn.cursor() res = cursor.execute(sql, args).fetchall() return res #执行sql或者查询列表 并提交 def execute(self, sql, *args): args = self.turnArray(args) self.out(sql, args) conn = self.getConn() cursor = conn.cursor() #sql占位符 填充args 可以是tuple(1, 2)(动态参数数组) 也可以是list[1, 2] list(tuple) tuple(list) res = cursor.execute(sql, args).fetchall() conn.commit() #self.close(conn) return res #查询列名列表array[str] eg: ['id', 'name', 'birth'] def getColumnNames(self, sql, *args): args = self.turnArray(args) self.out(sql, args) conn = self.getConn() if(not conn is None): cursor = conn.cursor() cursor.execute(sql, args) res = [tuple[0] for tuple in cursor.description] return res #查询结果为单str eg: 'xxxx' def getString(self, sql, *args): args = self.turnArray(args) self.out(sql, args) conn = self.getConn() cursor = conn.cursor() listRes = cursor.execute(sql, args).fetchall() columnNames = [tuple[0] for tuple in cursor.description] #print(columnNames) res = "" if(listRes and len(listRes) >= 1): res = listRes[0][columnNames[0]] return res #查询记录数量 自动附加count(*) eg: 3 def getCount(self, sql, *args): args = self.turnArray(args) sql = "select count(*) cc from ( " + sql + " ) " resString = self.getString(sql, args) res = 0 if(resString): res = int(resString) return res####################################测试def main(): db = database() db.execute( ''' create table if not exists student( id text primary key, name text not null, birth text ) ''' ) for i in range(10): db.execute("insert into student values('id1" + str(i) + "', 'name1" + str(i) + "', 'birth1" + str(i) + "')") db.execute("insert into student values('id01', 'name01', 'birth01')") db.execute("insert into student values('id02', 'name02', 'birth01')") db.execute("insert into student values('id03', 'name03', 'birth01')") print(db.getColumnNames("select * from student")) print(db.getCount("select * from student " )) print(db.getString("select name from student where id = ? ", "id02" )) print(db.executeQuery("select * from student where 1=? and 2=? ", 1, 2 )) print(db.executeQueryPage("select * from student where id like ? ", 1, 5, "id0%")) db.execute("update student set name='nameupdate' where id = ? ", "id02") db.execute("delete from student where id = ? or 1=1 ", "id01") db.close()if __name__ == '__main__': main() |
希望本文所述对大家Python程序设计有所帮助。
原文链接：https://blog.csdn.net/u014303844/article/details/78963812
