mongodb update command($inc/$set/$unset/$push/$pop/upsert/save)

2019-09-1119:58:51 Comment

In addition to replacement, only partial updates are needed for one or more documents. Atomic update modifiers can be used to update documents efficiently. Update modifier is a special key.

Used to specify complex operations, such as adding, deleting, or adjusting keys, and possibly an array of operations or embedded documents.

1、$inc --The modifier $inc can add or subtract keys with a value of a document that is numeric (only the number that meets the requirements).

{"uid":"201203","type":"1",size:10}

> db.b.insert({"uid":"201203","type":"1",size:10})
> db.b.find()
{ "_id" : ObjectId("5003b6135af21ff428dafbe6"), "uid" : "201203", "type" : "1",
"size" : 10 }
> db.b.update({"uid" : "201203"},{"$inc":{"size" : 1}})
> db.b.find()
{ "_id" : ObjectId("5003b6135af21ff428dafbe6"), "uid" : "201203", "type" : "1",
"size" : 11 }
> db.b.update({"uid" : "201203"},{"$inc":{"size" : 2}})
> db.b.find()
{ "_id" : ObjectId("5003b6135af21ff428dafbe6"), "uid" : "201203", "type" : "1",
"size" : 13 }
> db.b.update({"uid" : "201203"},{"$inc":{"size" : -1}})
> db.b.find()
{ "_id" : ObjectId("5003b6135af21ff428dafbe6"), "uid" : "201203", "type" : "1",
"size" : 12 }

2、$set

> db.a.findOne({"uid" : "20120002","type" : "3"})
{ "_id" : ObjectId("500216de81b954b6161a7d8f"), "desc" : "hello world2!", "num"
: 40, "sname" : "jk", "type" : "3", "uid" : "20120002" }
--size键不存在的场合
> db.a.update({"uid" : "20120002","type" : "3"},{"$set":{"size":10}})
> db.a.findOne({"uid" : "20120002","type" : "3"})
{ "_id" : ObjectId("500216de81b954b6161a7d8f"), "desc" : "hello world2!", "num"
: 40, "size" : 10, "sname" : "jk", "type" : "3", "uid" : "20120002" }
--sname键存在的场合
> db.a.update({"uid" : "20120002","type" : "3"},{"$set":{"sname":"ssk"}})
> db.a.find()
{ "_id" : ObjectId("500216de81b954b6161a7d8f"), "desc" : "hello world2!", "num"
: 40, "size" : 10, "sname" : "ssk", "type" : "3", "uid" : "20120002" }
{ "_id" : ObjectId("50026affdeb4fa8d154f8572"), "desc" : "hello world1!", "num"
: 50, "sname" : "jk", "type" : "1", "uid" : "20120002" }
--可改变键的值类型
> db.a.update({"uid" : "20120002","type" : "3"},{"$set":{"sname":["Java",".net","c++"]}})
> db.a.findOne({"uid" : "20120002","type" : "3"})
{
        "_id" : ObjectId("500216de81b954b6161a7d8f"),
        "desc" : "hello world2!",
        "num" : 40,
        "size" : 10,
        "sname" : [
                "java",
                ".net",
                "c++"
        ],
        "type" : "3",
        "uid" : "20120002"
}

For embedded documents, how does $set update embedded documents? See the following example:

{"name":"toyota","type":"suv","size":{"height":10,"width":5,"length":15}}

> db.c.findOne({"name":"toyota"})
{
        "_id" : ObjectId("5003be465af21ff428dafbe7"),
        "name" : "toyota",
        "type" : "suv",
        "size" : {
                "height" : 10,
                "width" : 5,
                "length" : 15
        }
}
> db.c.update({"name":"toyota"},{"$set":{"size.height":8}})
> db.c.findOne({"name":"toyota"})
{
        "_id" : ObjectId("5003be465af21ff428dafbe7"),
        "name" : "toyota",
        "type" : "suv",
        "size" : {
                "height" : 8,
                "width" : 5,
                "length" : 15
        }
}
> db.c.update({"name":"toyota"},{"$set":{"size.width":7}})
> db.c.findOne({"name":"toyota"})
{
        "_id" : ObjectId("5003be465af21ff428dafbe7"),
        "name" : "toyota",
        "type" : "suv",
        "size" : {
                "height" : 8,
                "width" : 7,
                "length" : 15
        }
}

3、$unset -- When using the modifier $unset, you can delete the target key whether you use 1, 0, -1, or a specific string for the target key.

> db.a.update({"uid" : "20120002","type" : "3"},{"$unset":{"sname":1}})
> db.a.findOne({"uid" : "20120002","type" : "3"})
{
        "_id" : ObjectId("500216de81b954b6161a7d8f"),
        "desc" : "hello world2!",
        "num" : 40,
        "size" : 10,
        "type" : "3",
        "uid" : "20120002"
}
> db.a.update({"uid" : "20120002","type" : "3"},{"$unset":{"num":0}})
> db.a.findOne({"uid" : "20120002","type" : "3"})
{
        "_id" : ObjectId("500216de81b954b6161a7d8f"),
        "desc" : "hello world2!",
        "size" : 10,
        "type" : "3",
        "uid" : "20120002"
}
> db.a.update({"uid" : "20120002","type" : "3"},{"$unset":{"size":-1}})
> db.a.findOne({"uid" : "20120002","type" : "3"})
{
        "_id" : ObjectId("500216de81b954b6161a7d8f"),
        "desc" : "hello world2!",
        "type" : "3",
        "uid" : "20120002"
}
> db.a.update({"uid" : "20120002","type" : "3"},{"$unset":{"desc":"sssssss"}})
> db.a.findOne({"uid" : "20120002","type" : "3"})
{
        "_id" : ObjectId("500216de81b954b6161a7d8f"),
        "type" : "3",
        "uid" : "20120002"
}

4、$push -- Add an array element to the key of an array type of the document, but filter out duplicate data. Adding a key exists, requiring that the key value type must be an array; if the key does not exist, the key of the array type is created.

> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "type" : "suv",
"size" : { "height" : 8, "width" : 7, "length" : 15 } }
> db.c.update({"name" : "toyota"},{$push:{"title":"t1"}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1" ], "type" : "suv" }
> db.c.update({"name" : "toyota"},{$push:{"title":"t2"}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t2" ], "type" : "suv" }

5、 $ne/$addToSet 

> db.c.update({"title" : {$ne:"t2"}},{$push:{"title":"t2"}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t2", "t2" ], "type" : "suv" }

> db.c.update({"name" : "toyota"},{$addToSet:{"title":"t2"}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t2", "t2" ], "type" : "suv" }

6、 $pop、$pull 

{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t2", "t3", "t4" ],"type" : "suv" }

delete from array tail 1
> db.c.update({"name" : "toyota"},{$pop:{"title":1}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t2", "t3" ], "type" : "suv" }

delete from array head -1
> db.c.update({"name" : "toyota"},{$pop:{"title":-1}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t2", "t3" ], "type" : "suv" }

delete from array tail 0
> db.c.update({"name" : "toyota"},{$pop:{"title":0}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t2" ], "type" : "suv" }

delete from array with condition
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t2", "t2", "t3" ],"type" : "suv" }
 
> db.c.update({"name" : "toyota"},{$pull:{"title":"t2"}})
> db.c.find()
{ "_id" : ObjectId("5003be465af21ff428dafbe7"), "name" : "toyota", "size" : { "height" : 8,
 "width" : 7, "length" : 15 }, "title" : [ "t1", "t3" ], "type" : "suv" }

7、Array Location Modifier

{"uid":"001",comments:[{"name":"t1","size":10},{"name":"t2","size":12}]}

> db.c.find({"uid":"001"})
{ "_id" : ObjectId("5003da405af21ff428dafbe8"), "uid" : "001", "comments" : [ {
"name" : "t1", "size" : 10 }, { "name" : "t2", "size" : 12 } ] }
> db.c.update({"uid":"001"},{$inc:{"comments.0.size":1}})
> db.c.find({"uid":"001"})
{ "_id" : ObjectId("5003da405af21ff428dafbe8"), "uid" : "001", "comments" : [ {
"name" : "t1", "size" : 11 }, { "name" : "t2", "size" : 12 } ] }
> db.c.update({"comments.name":"t1"},{$set:{"comments.$.size":1}})
> db.c.find({"uid":"001"})
{ "_id" : ObjectId("5003da405af21ff428dafbe8"), "uid" : "001", "comments" : [ {
"name" : "t1", "size" : 1 }, { "name" : "t2", "size" : 12 } ] }

8、upsert

> db.c.remove()
> db.c.update({"size":11},{$inc:{"size":3}})
> db.c.find()
> db.c.update({"size":11},{$inc:{"size":3}},false)
> db.c.find()
> db.c.update({"size":11},{$inc:{"size":3}},true)
> db.c.find()
{ "_id" : ObjectId("5003ded6c28f67507a6df1de"), "size" : 14 }

9、save

> db.a.find()
{ "_id" : ObjectId("50026affdeb4fa8d154f8572"), "desc" : "hello world1!", "num": 50,
 "sname" : "jk", "type" : "1", "uid" : "20120002" }
> var o = db.a.findOne()
> o.num = 55
55
> db.a.save(o)
> db.a.find()
{ "_id" : ObjectId("50026affdeb4fa8d154f8572"), "desc" : "hello world1!", "num": 55,
 "sname" : "jk", "type" : "1", "uid" : "20120002" }

Comment

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