MongoDB Python – 插入和替换操作

先决条件： MongoDB Python基础
本文重点介绍如何替换集合内的文档或条目。我们只能替换已经插入数据库的数据。
使用的方法： replace_one() 和 replace_many()
目的：用新文档替换旧文档的全部数据

MongoDB中的插入

我们将首先在 MongoDB 中插入数据。

# Python code to illustrate
# Insert in MongoDB
from pymongo import MongoClient
  
try:
    conn = MongoClient()
    print("Connected successfully!!!")
except:  
    print("Could not connect to MongoDB")
  
# database
db = conn.database
  
# Created or Switched to collection names: my_gfg_collection
collection = db.my_gfg_collection
  
emp_rec1 = {
        "name":"Mr.Geek",
        "eid":24,
        "location":"delhi"
        }
emp_rec2 = {
        "name":"Mr.Shaurya",
        "eid":14,
        "location":"delhi"
        }
emp_rec3 = {
        "name":"Mr.Coder",
        "eid":14,
        "location":"gurugram"
        } 
  
# Insert Data
rec_id1 = collection.insert_one(emp_rec1)
rec_id2 = collection.insert_one(emp_rec2)
rec_id3 = collection.insert_one(emp_rec3)
print("Data inserted with record ids",rec_id1," ",rec_id2,rec_id3)
  
# Printing the data inserted
cursor = collection.find()
for record in cursor:
    print(record)

输出：

Connected successfully!!!
Data inserted with record ids    
{'_id': ObjectId('5a02227b37b8552becf5ed2a'), 'name': 
'Mr.Geek', 'eid': 24, 'location': 'delhi'}
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name': 
'Mr.Shaurya', 'eid': 14, 'location': 'delhi'}
{'_id': ObjectId('5a02227c37b8552becf5ed2c'), 'name': 
'Mr.Coder', 'eid': 14, 'location': 'gurugram'}

替换_one()

插入数据后，让我们替换名称为：Mr.Shaurya 的员工的数据

# Python code to illustrate 
# Replace_one() in MongoDB
from pymongo import MongoClient 
  
try:
    conn = MongoClient()
    print("Connected successfully!!!")
except:  
    print("Could not connect to MongoDB")
  
# database
db = conn.database
  
# Created or Switched to collection names: my_gfg_collection
collection = db.my_gfg_collection
  
# replace one of the employee data whose name is Mr.Shaurya
result = collection.replace_one(
        {"name":"Mr.Shaurya"},
        {
                "name":"Mr.GfG",
                "eid":45,
                "location":"noida"
                  
                }
        )
  
print("Data replaced with id",result)
  
# Print the new record
cursor = collection.find()
for record in cursor:
    print(record)

Connected successfully!!!
Data replaced with id 
{'_id': ObjectId('5a02227b37b8552becf5ed2a'), 'name': 
'Mr.Geek', 'eid': 24, 'location': 'delhi'}
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name': 
'Mr.GfG', 'eid': 45, 'location': 'noida'}
{'_id': ObjectId('5a02227c37b8552becf5ed2c'), 'name': 
'Mr.Coder', 'eid': 14, 'location': 'gurugram'}

我们已成功替换员工姓名：'Mr.Shaurya' 的文档，并将整个文档替换为新的，姓名：'Mr.GfG'（现在）。

Replace_many()

考虑到数据与插入的数据相同。
用 eid:14 替换所有数据条目。

# Python code to illustrate 
# Replace_many() in MongoDB
from pymongo import MongoClient
  
try:
    conn = MongoClient()
    print("Connected successfully!!!")
except:  
    print("Could not connect to MongoDB")
  
# database
db = conn.database
  
# Created or Switched to collection names: my_gfg_collection
collection = db.my_gfg_collection
  
# replace one of the employee data whose name is Mr.Shaurya
result = collection.replace_many(
        {"eid":14},
        {
                "name":"Mr.GfG",
                "eid":45,
                "location":"noida"
                  
                }
        )
  
print("Data replaced with id",result)
  
# Print the new record
cursor = collection.find()
for record in cursor:
    print(record)

输出将是：

Connected successfully!!!
Data replaced with id 
{'_id': ObjectId('5a02227b37b8552becf5ed2a'), 'name': 
'Mr.Geek', 'eid': 24, 'location': 'delhi'}
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name': 
'Mr.GfG', 'eid': 45, 'location': 'noida'}
{'_id': ObjectId('5a02227c37b8552becf5ed2c'), 'name': 
'Mr.GfG', 'eid': 45, 'location': 'noida'}

在这里，我们可以看到两个带有 eid:14 的条目都被新数据替换了。 （即使数据相同，ObjectId 也会不同）。