如何在python中为Sql语句提供动态输入

Question

我正在尝试用python执行一个动态sql查询。它看起来像下面

import json
from decimal import Decimal
import psycopg2

def initial_execution(param_name):
    time = get_timestamp(param_name)
    query = 'SELECT name, account_mgr, addr1, addr2, ap_email, bill_to_nbr, billto_only, city, controlling_nbr, controlling_only, country, cust_contact, email, load_create_date, load_update_date, nbr, owner, sales_rep, source_system, state, station, zip FROM public.customers WHERE billto_only = 'Y' OR controlling_only = 'Y' AND load_create_date >= \''+time+'\' OR load_update_date >= \''+time+'\''
    queryData = execute_db_query(query)

执行\u db\u查询->；此函数使用pscopg2以红移方式运行 我通过从用户输入中动态提取“时间”来执行此脚本。我犯了一个错误

[ERROR] Runtime.UserCodeSyntaxError: Syntax error in module
'src/customers': 
invalid syntax (customers.py, line 78) 
Traceback
(most recent call last):   File "/var/task/src/customers.py" 
Line 78 query = 'SELECT name,billto_only, controlling_only , load_create_date, load_update_date, nbr, owner, sales_rep,
 source_system, state, station, zip FROM public.test WHERE billto_only
 = 'Y' OR controlling_only = 'Y' AND load_create_date >= \''+time+'\' OR load_update_date >= \''+time+'\''

sql中的相同查询如下所示编写并正确执行

SELECT name,billto_only,  controlling_only,load_create_date, load_update_date, nbr, owner, sales_rep, source_system, state, station, zip FROM public.test
WHERE (billto_only = 'Y' OR controlling_only = 'Y') AND (load_create_date >= '2020-10-09 07:04:51' OR load_update_date >= '2020-10-09 07:04:51') limit 5;

Answer 1

发生错误的原因是'符号

"SELECT name, account_mgr, addr1, addr2, ap_email, bill_to_nbr, billto_only, city, controlling_nbr, controlling_only, country, cust_contact, email, load_create_date, load_update_date, nbr, owner, sales_rep, source_system, state, station, zip FROM public.customers WHERE billto_only = 'Y' OR controlling_only = 'Y' AND load_create_date >= '{date}' OR load_update_date >= '{date}'".format(date=time)

Answer 2

可能有点不对劲，但“Y”会打断你的弦吗

query = 'SELECT name,billto_only, controlling_only , load_create_date, load_update_date, nbr, owner, sales_rep, source_system, state, station, zip FROM public.test WHERE billto_only = \'Y\' OR controlling_only = \'Y\' AND load_create_date >= \''+time+'\' OR load_update_date >= \''+time+'\''

省略撇号

Answer 3

正确的方法是：

query = """SELECT 
name, account_mgr, addr1, addr2, ap_email, bill_to_nbr, billto_only, city, controlling_nbr, 
controlling_only, country, cust_contact, email, load_create_date, load_update_date, nbr, 
owner, sales_rep, source_system, state, station, zip 
FROM 
    public.customers 
WHERE 
    billto_only = 'Y' OR controlling_only = 'Y' 
AND 
    load_create_date >= %(time_val)s OR load_update_date >= %(time_val)s
"""

queryData = execute_db_query(query, {"time_val": time)

以上内容确保传入的数据正确引用，并防止SQL注入问题。 我还避免使用变量名，如time。这与Postgres中的time模块以及time类型存在潜在冲突