Python＞＞SQL我只写复制粘贴的

介绍

写sql字段太多核对编写起来太累了,公司项目又紧,一星期3000多行sql,要各种转换调用各种接口,所以为了提高工作效率,争取更多时间(摸鱼),我就用python了,相对于其它重复的敲小伙伴,我就直接飞起,现向大家展示个人比较常用的编写sql的代码

1.字段取别名

如果还在手动的赋值粘贴表别名,你就累了,我直接反手一正则

import re

table_AS = 'td.'
schema = '[dbo].'
SQL = f"""SELECT {table_AS}Id,CreateTime,shenpibianma,xingming,gonghao,bumen,shenpizhuangtai,wanchengshijian,zhuti,feiyongbaoxiaozonge,beizhu,fujian
"""
print(re.sub(',', f',{table_AS}', str(SQL), SQL.count(',')))

运行结果:

SELECT td.Id,td.CreateTime,td.shenpibianma,td.xingming,td.gonghao,td.bumen,td.shenpizhuangtai,td.wanchengshijian,td.zhuti,td.feiyongbaoxiaozonge,td.beizhu,td.fujian

re模块中的sub类似于字符串函数replace匹配进行替换

语法re.sub(pattern,repl,string,count);

pattern:正则中的模式字符串,repl:要替换的字符串,string:原始字符串,count:替换几次

而str.count(',')就是在统计逗号出现的次数,进而对应sub函数的替换次数

2.CASE WHEN批量转换

data_value = "我是谁,ice,_,Seattle"
field_name = 'Demo_test'
data_value = data_value.split(',')
index_range = len(data_value)
sql = ['']


def case_when():
    for i in range(0, index_range - 1):
        sql.append('')
    for i in range(0, index_range, 1):
        sql[i] = f"""    WHEN {field_name} = '{i}' THEN '{data_value[i]}' \n"""
    return ''.join(map(str, sql))

运行结果:

CASE
WHEN Demo_test = '0' THEN '我是谁'
WHEN Demo_test = '1' THEN 'ice'
WHEN Demo_test = '2' THEN '_'
WHEN Demo_test = '3' THEN 'Seattle'
ELSE '请选择' END Demo_test,

以为很方便,确实很方便,结合起来更方便,对于特殊情况,例如case when中出现 or 或 and,

PATINDEX('%[^0-9|.|-|+]%', 字段)=0 THEN (SELECT Name FROM Areas where ID = 字段)

等可以根据具体情况进行更改

3.批量生成表名,字段名系列

实现逻辑,通过sql语句查询系统中的所有表名,字段名,格式化输出成需要的格式进行输出,此处用的正则,其中/..../g表示全文匹配,此处用的sql server

其中使用

SELECT NAME FROM SYSOBJECTS WHERE XTYPE='u' 获取数据库中所有表名

select name from syscolumns where id=(select max(id) from sysobjects where xtype='u' and name = '数据表') 获取所查表的所有字段名

import re
import pymssql

server = '192.168.10.10'
user = "账号"
password = "密码"
database = "数据库"
connect = pymssql.connect(server, user, password, database)
cursor = connect.cursor()
cursor.execute("select name from sysobjects where xtype='u'")
# print(cursor.fetchall())

Data_Tab = cursor.fetchall()
data_table = re.sub('[/\\[\\](,)\'*/g]', f'', str(Data_Tab))
print(re.sub('[/ /g]', f'\n', str(data_table)))
'''
for i in range(0, len(list_data)):
    print(list_data[i])
'''
# 获取指定表列名
cursor.execute("select name from syscolumns where id=(select max(id) from sysobjects where xtype='u' and name = 'Areas')")
Data_Col = cursor.fetchall()
data_column = re.sub('[/\\[\\]()\'*/g]', f'', str(Data_Col))
print(data_column.replace(',,', ','))

运行结果如下,数据表很多只列举部分

RF_ProramButton
RF_ProramExport
RF_ProramField
RF_ProramQuery
RF_ProramValidate
RF_SystemButton
RF_Test
RF_Test1Sub
RF_TestSub
RF_UserFileShare
RF_UserShortcut
RF_Vote
RF_VoteItem
RF_VoteItemOption
RF_VotePartakeUser
RF_VoteResult
RF_VoteResultUser
RF_WorkDate
RF_WorkGroup
RF_DbConnection

ID, ParentId, ReionId, Name, MererName, ShortName, MererShortName, LevelType, CityCode, ZipCode, Pinyin, Jianpin, FirstChar, Ln, Lat, Remark, Order, IsDelete, InsertTime,

这样在写程序SQL对应字段编写中就会很快,与其它小程序可以灵活搭配

4.数字加引号

def use_re(e):
    value = int(e.group('value'))
    return f"'{str(value)}'"


sql = """
case 
when Staff_Category = 1 then '请选择' 
when Staff_Category = 2 then '试用期员工' 
when Staff_Category = 3 then '正式员工'
when Staff_Category = 5 then '劳务（全职）' 
when Staff_Category = 6 then '劳务（兼职）'
when Staff_Category = 7 then '岗位外包'  
when Staff_Category = 9 then '劳务(临时工)' 
when Staff_Category = 10 then '返聘'  
when Staff_Category = 11 then '特聘' 
else '' end Staff_Category
"""

elements = re.sub('(?P<value>\\d+)', use_re, ''.join(map(str, sql)), count=0, flags=0)
print(f'{elements}')

正则\d匹配数字类型,pycharm中用\\d表示,将sql粘贴在sql区域内就可以批量对数字加引号,对于前后端的类型转换是有用的

运行结果如下

case
when Staff_Category = '1' then '请选择'
when Staff_Category = '2' then '试用期员工'
when Staff_Category = '3' then '正式员工'
when Staff_Category = '5' then '劳务（全职）'
when Staff_Category = '6' then '劳务（兼职）'
when Staff_Category = '7' then '岗位外包'
when Staff_Category = '9' then '劳务(临时工)'
when Staff_Category = '10' then '返聘'
when Staff_Category = '11' then '特聘'
else '' end Staff_Category

5.sql字段多值截取

在数据库中会遇到一个字段存储的值为 1,3,2等,对于case when输出展示在系统上判断在不在('1','2','3')并不友好,而stuff()也不能解决这种情况,需要substring()与charindex()结合使用,其中

CHARINDEX(substring, string [, start_location])

substring为要搜的字符串,string为被搜索的字符串,此处用的数据表字段

start_location参数可选,为搜索起始位置

对此我针对这一类问题写了截取判断 in (范围)的情况

import re


def use_re(e):
    value = int(e.group('value'))
    return f"'{str(value)}'"


field = 'seal'  
values = '2,4,7,8'
index_range = 1
sql = ['']
for i in range(0, len(values) - 1):
    sql.append('')
for i in range(0, len(values), 2):
    sql[i] = f"""SUBSTRING({field}, charindex({values[i]},{field}), {index_range}) not in ({values}) AND \n"""


elements = re.sub('(?P<value>[2-9]+)', use_re, ''.join(map(str, sql)), count=0, flags=0)
print(f'{elements}')

运行效果如下

SUBSTRING(seal, charindex('2',seal), 1) not in ('2','4','7','8') AND
SUBSTRING(seal, charindex('4',seal), 1) not in ('2','4','7','8') AND
SUBSTRING(seal, charindex('7',seal), 1) not in ('2','4','7','8') AND
SUBSTRING(seal, charindex('8',seal), 1) not in ('2','4','7','8') AND

以上就是五种常用小模块,后续会写在图形界面上

Python＞＞SQL我只写复制粘贴的

介绍

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