Question

我有以下查询从PostgreSQL中检索数据。

select_stmt = "SELECT * FROM kart_user WHERE token = %(token)s"
cursor.execute(select_stmt, { 'token': 2 })

某些案例字典可能包含多个键和值
例如 -

{ 'token': 10,'custid':100,cycle:"yes" }

在这种情况下，我如何动态指定列名称及其值？

我试过了..

select_stmt = "SELECT * FROM kart_user WHERE dist.keys() = %(dist.keys())s"
cursor.execute(select_stmt, dist)

但没有运气。谢谢你的回复..

Answer 1

根据您尝试过的声明，我假设您有三个键和三个值，因此您希望逐个执行所有三个的SELECT语句。以下解决方案将为您提供帮助。

docker exec --it <running_container> bash

@对于和条件

d = { 'token': 10,'custid':100,cycle:"yes" }
select_stmt = "SELECT * FROM kart_user WHERE {key} = '{value}'"
allowed_col = ['token', 'custid'] # Predefined column names to allow from coming dictionary.
for key, value in d.iteritems():
    if  key in allowed_col:
        select_stmt = select_stmt.format(key=key, value=value)
        cursor.execute(select_stmt, dist)
        # Further fetching code you can execute. Here you will get select statement for particular key and value.

以上答案的一个班轮解决方案，

d = { 'token': 10,'custid':100,'cycle':"yes" }
select_stmt = "SELECT * FROM kart_user WHERE"
allowed_col = ['token', 'custid'] # Predefined column names to allow from coming dictionary.
for key, value in d.iteritems():
    if  key in allowed_col:
        condition = "{key} = '{value}'".format(key=key, value=value)
        select_stmt = select_stmt + " and " + condition
cursor.execute(select_stmt, dist)
# Further fetching code you can execute. Here you will get select statement for particular key and value.

如果您的查询不同，那么我的答案就会回复。感谢。

Python字符串替换动态列名称和值

1 个答案: