def upsert_example():
"""upsert的意思是: 首先尝试update, 如果找不到该文档, 则insert改文档
"""
users.update({"name": "obama"}, {"$set": {"name": "obama"}}, upsert=True)
fmter.tpl._straightline("after", 100)
for doc in users.find({"name": "obama"}):
ppt(doc)
def multiUpdate():
# users.update({}, {"name": "obama"}) # only one document are updated
users.update({}, {"$set": {"name": "obama"}}, multi=True) # all document matching where clause are updated
for doc in users.find():
ppt(doc)
# multiUpdate()
def unset():
"""移除掉某一个key, 请使用"$unset"
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$unset": {"profile": 1}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def push():
"""在右边添加一项, 相当于list.append(item)
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$push": {"skillset": "data visualization"}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def unset():
"""移除掉某一个key, 请使用"$unset"
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$unset": {"profile": 1}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def pop():
"""在右边取出一项, 相当于list.pop()
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$pop": {"skillset": 1}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def addToSet():
"""将array当成set来执行set.add(item)操作
"""
users.update({"_id": 1}, {"$push": {"skillset": "python"}}) # 先加一个python, 故意添加重复项
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$addToSet": {"skillset": "R"}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0]) # 只会在添加的时候将其当成set处理, 并不会把array自动转化为set
def pullall():
"""删除多项, 相当于 for i in list, if i in [item1, item2, ...], list.remove(i)
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$pullAll": {"skillset": ["python", "cSharp", "R"]}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def pull():
"""删除所有的某项, 相当于 for i in list, if i == pull_item, list.remove(i)
"""
users.update({"_id": 1}, {"$push": {"skillset": "python"}}) # 先加一个python, 故意添加重复项
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$pull": {"skillset": "python"}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0]) # 把所有的python, 包括重复项都删除了
def pushAll():
"""在右边加上多项, 相当于 list = list + another_list
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$pushAll": {"skillset": ["data visualization", "R"]}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def pop():
"""在右边取出一项, 相当于list.pop()
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$pop": {"skillset": 1}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def push():
"""在右边添加一项, 相当于list.append(item)
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$push": {"skillset": "data visualization"}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def multiUpdate():
# users.update({}, {"name": "obama"}) # only one document are updated
users.update({}, {"$set": {
"name": "obama"
}}, multi=True) # all document matching where clause are updated
for doc in users.find():
ppt(doc)
# multiUpdate()
def update_without_set():
"""若不使用collection.update(query, {"$set": {key: value}), 而使用:
collection.update(query, new_document)
则会将所有定位到的document替换成, new_document
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"_id": 1}) # replace the whole document with the new one
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def addToSet():
"""将array当成set来执行set.add(item)操作
"""
users.update({"_id": 1}, {"$push": {
"skillset": "python"
}}) # 先加一个python, 故意添加重复项
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$addToSet": {"skillset": "R"}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0]) # 只会在添加的时候将其当成set处理, 并不会把array自动转化为set
def pull():
"""删除所有的某项, 相当于 for i in list, if i == pull_item, list.remove(i)
"""
users.update({"_id": 1}, {"$push": {
"skillset": "python"
}}) # 先加一个python, 故意添加重复项
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1}, {"$pull": {"skillset": "python"}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0]) # 把所有的python, 包括重复项都删除了
def pushAll():
"""在右边加上多项, 相当于 list = list + another_list
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1},
{"$pushAll": {
"skillset": ["data visualization", "R"]
}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def pullall():
"""删除多项, 相当于 for i in list, if i in [item1, item2, ...], list.remove(i)
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
users.update({"_id": 1},
{"$pullAll": {
"skillset": ["python", "cSharp", "R"]
}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
def insept_example():
"""insept的意思是: 首先尝试insert, 如果面临着_id重复问题, 则update
该逻辑可以用upsert实现。注: 有时候document是没有包含_id项的
"""
doc = {"_id": 1, "name": "obama", "new_field": 999}
try:
users.insert(doc)
except:
_id = doc["_id"]
del doc["_id"]
users.update({"_id": _id}, {"$set": doc}, upsert=True)
ppt(users.find({"name": "obama"})[0])
# insept_example()
def absolute_update():
"""collection.update()语法分两部分, 第一部分是定位到需要修改的document, 第二部分是对值
进行设定。
注意:
使用 "$set": {key: value} 只会对key的部分进行修改, 如果使用:
users.update({"_id": 1}, {"name": "obama"}), 则会将整个文档替换成 {"name": "obama"}
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
ppt(users.find({"_id": 2})[0])
users.update({"_id": 1}, {"$set": {"name": "obama", # update name field
"profile.enthnicity": "african american"}}) # access child
users.update({"name": "michael"}, {"age": 100}) # replace whole document, only keep _id
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
ppt(users.find({"_id": 2})[0])
def relative_update():
"""在Sql中有 set column_name = column_name + 1 这种相对更新的方法。在mongodb中我们的做法是:
1. 使用$inc, $mul等操作符: http://docs.mongodb.org/manual/reference/operator/update-field/
2. 首先find()找到document, 然后修改document对象, 最后再collection.save(document)保存改动。
"""
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 1})[0])
doc = users.find_one({"_id": 1}) # find the document
doc["age"] += 30 # do some change to the document
users.save(doc) # save changes into collections
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 1})[0])
fmter.tpl._straightline("before", 100)
ppt(users.find({"_id": 2})[0])
users.update({"_id": 2}, {"$inc": {"age": 30}})
fmter.tpl._straightline("after", 100)
ppt(users.find({"_id": 2})[0])