MongoDB快速入门笔记(六)之MongoDB的文档修改操作
MongoDB
MongoDB是一个开源的文档数据库，并领先的NoSQL数据库。MongoDB是由c++语言编写。
文档
文档是一组键-值对。文件动态模式。动态模式是指，在相同集合中的文档不需要具有相同的字段或结构组的公共字段的集合的文档，可以容纳不同类型的数据。
db.集合名称.update({query},{update},upsert,multi})
query:过滤条件
update:修改内容
upsert：如果不存在查询条件查出的记录，是否插入一条数据，默认是false
multi：是否只修改查询条件查出的第一条记录，默认是false
>db.student.update({_id:1},{name:"zhang"})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhang"}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
把整条数据都修改了，如果修改内容中没有设置age字段，则以前的age也取消了，数据全部修改
局部修改
$set:如果存在键则修改，如果不存在键则添加
>db.student.update({_id:1},{$set:{name:"zhangsan",age:26}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
id重复时无法修改
>db.student.update({_id:1},{_id:0,name:"zhangsanzhangsan"})
WriteResult({
"nMatched":0,
"nUpserted":0,
"nModified":0,
"writeError":{
"code":16837,
"errmsg":"The_idfieldcannotbechangedfrom{_id:1.0}to{_id:0.0}."
}
})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
第三个参数默认为false，如果查不到数据false时不执行任何操作，true时往数据库里新插入一条数据
>db.student.update({_id:7},{_id:7,name:"songjiu",age:32})
WriteResult({"nMatched":0,"nUpserted":0,"nModified":0})
>db.student.update({_id:7},{_id:7,name:"songjiu"},true)
WriteResult({"nMatched":0,"nUpserted":1,"nModified":0,"_id":7})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","age":32}
第四个参数默认为false，false时表示只修改查询到的第一条数据，true时表示修改查询到的所有数据
>db.student.update({age:32},{$set:{age:33}},false,false)
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":33}
{"_id":7,"name":"songjiu","age":32}
>db.student.update({age:33},{$set:{age:32}},false,true)
WriteResult({"nMatched":2,"nUpserted":0,"nModified":2})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":32}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","age":32}
>db.student.update({age:32},{$set:{age:33}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","age":32}
$inc:在原来的基础上加多少
>db.student.update({_id:7},{$inc:{age:-1}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","age":31}
$unset:去掉某个键
>db.student.update({_id:7},{$unset:{age:1}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu"}
针对数组类型的操作
$push:当数据中不存在键时，创建数组类型的键并插入该值;如果存在该键，并且该键是数组类型时，则在此数组类型的数据上追加;如果存在该键，并且该键不是数组类型时，会报错。
$pushAll:批量往数组中追加
$addToSet:数组中有该值时不追加，没有该值时追加
>db.student.update({_id:7},{$push:{skill:"java"}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["java"]}
>db.student.update({_id:7},{$push:{skill:"mongodb"}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["java","mongodb"]}
>db.student.update({_id:7},{$push:{name:"111"}})
WriteResult({
"nMatched":0,
"nUpserted":0,
"nModified":0,
"writeError":{
"code":16837,
"errmsg":"Thefield'name'mustbeanarraybutisoftypeStringindocument{_id:7.0}"
}
})
>db.student.update({_id:7},{$pushAll:{skill:["js","C++","java"]}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["java","mongodb","js","C++","java"]}
>db.student.update({_id:7},{$addToSet:{skill:"mongodb"}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":0})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["java","mongodb","js","C++","java"]}
$pop:删除数组的第一个或最后一个元素，值为-1时是删除第一个元素，值为1时是删除最后一个元素。
$pull:删除数组中的某一个指定的数值
$pullAll:删除数组中多个指定的数值
>db.student.update({_id:7},{$pop:{skill:1}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["java","mongodb","js","C++"]}
>db.student.update({_id:7},{$pop:{skill:-1}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["mongodb","js","C++"]}
>db.student.update({_id:7},{$pull:{skill:"js"}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["mongodb","C++"]}
>db.student.update({_id:7},{$pullAll:{skill:["js"]}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":0})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":["mongodb","C++"]}
>db.student.update({_id:7},{$pullAll:{skill:["mongodb","C++"]}})
WriteResult({"nMatched":1,"nUpserted":0,"nModified":1})
>db.student.find()
{"_id":1,"name":"zhangsan","age":26}
{"_id":2,"name":"lisi","age":27}
{"_id":3,"name":"wangwu","age":30}
{"_id":4,"name":"zhaoliu","age":28}
{"_id":5,"name":"qianliu","age":33}
{"_id":6,"name":"sunba","age":32}
{"_id":7,"name":"songjiu","skill":[]}