大家好，又见面了，我是全栈君。
1.插入操作
user = {"username":"lcq","sex":"man"}
db.user.insert(user)
2.更新
var lcq = db.user.findOne({"username":"lcq"}}
lcq.address = {"province":"shandong","location":"zoupin"}
lcq.haha = "hehhehe"
db.user.update({"username":"lcq"},lcq)
> db.user.update({"username":"lcq"},{$set:{"test":"test"}})
> db.user.findOne({"username":"lcq"})
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"haha" : "afdfdfd",
"sex" : "man",
"test" : "test",
"username" : "lcq"
}
> db.user.update({"username":"lcq"},{$unset:{"test":1}})
$unset删除某个字段
> lcq = db.user.findOne({"username":"lcq"})
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
>
>
> lcq.count = 1
> db.user.update({"username":"lcq"},lcq)
> db.user.update({"username":"lcq"},{$inc:{"count":2}})
$inc设置某个字段自增
> db.user.update({"username":"lcq"},{$set:{"friends":['zhangsan']}})
> db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 3,
"friends" : [
"zhangsan"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
> db.user.update({"username":"lcq"},{$push:{"friends":'lisi'}})
>
> db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 3,
"friends" : [
"zhangsan",
"lisi"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
$push向数组中加入新的值
> db.user.update({"username":"lcq"},{$addToSet:{"friends":'lisi'}})
>
> db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 3,
"friends" : [
"zhangsan",
"lisi"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
> db.user.update({"username":"lcq"},{$addToSet:{"friends":'xiaoming'}})
>
>
> db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 3,
"friends" : [
"zhangsan",
"lisi",
"xiaoming"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
>
可见使用$addToSet加入时，假设存在同样的值则不加入。
> db.user.update({"friends":"lisi"},{$set:{"friends.$":"join"}})
>
>
>
> db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 3,
"friends" : [
"zhangsan",
"join",
"xiaoming"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
使用$符进行数组的定位，实现更新数组特定位置的值。
> lcq = db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 3,
"friends" : [
"zhangsan",
"join",
"xiaoming"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
>
>
> lcq.count = 10
10
>
> db.user.save(lcq)
>
> db.user.findOne()
{
"_id" : ObjectId("55024de2849b70a4f670f413"),
"address" : {
"province" : "shandong",
"location" : "zoupin"
},
"count" : 10,
"friends" : [
"zhangsan",
"join",
"xiaoming"
],
"haha" : "afdfdfd",
"sex" : "man",
"username" : "lcq"
}
save方法在不存在时创建。存在时更新。
更加方便。
3.删除
> db.user.insert({"username":"zhangsan"})
> db.user.remove({"username":"zhangsan"})
版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 举报，一经查实，本站将立刻删除。
发布者：全栈程序员-站长，转载请注明出处：https://javaforall.net/115904.html原文链接：https://javaforall.net
