Python MongoDB – find_one_and_replace 查询

find_one_and_replace()方法搜索一个文档，如果找到则替换为 MongoDb 中给定的第二个参数。 find_one_and_replace()方法与find_one_and_update () 方法不同，它借助过滤器替换文档而不是更新现有文档。

Syntax: find_one_and_replace(filter, replacement, projection=None, sort=None, return_document=ReturnDocument.BEFORE, session=None, **kwargs)
Parameters 
filter: A query for replacement of a matched document. 
replacement: replacement document. 
projection: it is optional.A list of a field that should be returned in the result. 
sort: key, direction pair for the sort order of query. 
return_document: Return the original document without replacement. 
**kwargs: Additional commands. 
 

以下所有示例中使用的示例数据库：

示例 1：

Python3

import pymongo
 
    
# establishing connection
# to the database
client = pymongo.MongoClient("mongodb://localhost:27017/")
    
# Database name
db = client["mydatabase"]
    
# Collection name
col = db["gfg"]
 
# replace with the help of
# find_one_and_replace()
col.find_one_and_replace({'coursename':'SYSTEM DESIGN'},
                         {'coursename': 'PHP'})
 
# print the document after replacement
for x in col.find({}, {"_id":0, "coursename": 1, "price": 1 }):
    print(x)

输出：

示例 2：

Python3

import pymongo
    
    
# establishing connection
# to the database
client = pymongo.MongoClient("mongodb://localhost:27017/")
    
# Database name
db = client["mydatabase"]
    
# Collection name
col = db["gfg"]
 
# replace with the help of
# find_one_and_replace()
col.find_one_and_replace({'price':9999}, {'price':19999})
 
# print the document after replacement
for x in col.find({}, {"_id":0, "coursename": 1, "price": 1 }):
    print(x)

输出：