MongoDBPython|删除数据并删除集合

先决条件： MongoDB 基础知识、插入和更新

目的：删除数据库中集合的条目/文档。假定集合名称为“my_collection”。
使用的方法： delete_one() 或 delete_many()

• 移除所有符合条件的文档：以下操作移除所有符合指定条件的文档。

  result = my_collection.delete_many({"name": "Mr.Geek"})

• 要查看已删除的文档数量：

  print(result.deleted_count)

• 删除所有文件：
  方法 1：使用 delete_many() 删除所有文档

  result= my_collection.delete_many({})

  方法 2：使用 collection.remove() 删除所有文档

  result = my_collection.remove() 

  删除的最佳方法是删除集合，以便同时删除数据索引，然后在该插入数据中创建一个新集合。

• 删除一个集合：

  db.my_collection.drop()

我们首先在集合中插入一个文档，然后根据查询删除文档。

# Python program to illustrate 
# delete, drop and remove
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 document before deletion
cursor = collection.find()
for record in cursor:
    print(record)
  
# Delete Document with name : Mr Coder
result = collection.delete_one({"name":"Mr.Coder"})
  
# If query would have been delete all entries with eid:14
# use this
# result = collection.delete_many("eid":14})
   
cursor = collection.find()
for record in cursor:
print(record)

OUTPUT (comment line denoted by #)

Connected successfully!!!
Data inserted with record ids     
#Data INSERT
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name': 
'Mr.GfG', 'eid': 45, 'location': 'noida'}
{'_id': ObjectId('5a0c734937b8551c1cd03349'), 'name': 
'Mr.Shaurya', 'eid': 14, 'location': 'delhi'}
{'_id': ObjectId('5a0c734937b8551c1cd0334a'), 'name': 
'Mr.Coder', 'eid': 14, 'location': 'gurugram'}
#Mr.Coder is deleted
{'_id': ObjectId('5a02227c37b8552becf5ed2b'), 'name': 
'Mr.GfG', 'eid': 45, 'location': 'noida'}
{'_id': ObjectId('5a0c734937b8551c1cd03349'), 'name': 
'Mr.Shaurya', 'eid': 14, 'location': 'delhi'}