目錄

1.洗掉全部

2.洗掉符合條件

3.洗掉滿足條件的單條檔案

4.delete

1.洗掉全部

命令：

?> db.collection.remove({})

實體：

> db.test.insertMany(
... [
... {item:"鉛筆",price:2},
... {item:"鋼筆",price:60}
... ]
... )
{
        "acknowledged" : true,
        "insertedIds" : [
                ObjectId("608bbb44f85311b76bd558fa"),
                ObjectId("608bbb44f85311b76bd558fb")
        ]
}
> db.test.find().pretty()
{ "_id" : ObjectId("608bbb44f85311b76bd558fa"), "item" : "鉛筆", "price" : 2 }
{
        "_id" : ObjectId("608bbb44f85311b76bd558fb"),
        "item" : "鋼筆",
        "price" : 60
}
> db.test.remove({})
WriteResult({ "nRemoved" : 2 })
> db.test.find().pretty()
查詢無顯示

2.洗掉符合條件

命令：

> db.collection.remove({條件})

實體：

> db.test.insertMany( [ {item:"鉛筆",price:2}, {item:"鋼筆",price:60},{item:"毛筆",price:30}] )
{
        "acknowledged" : true,
        "insertedIds" : [
                ObjectId("608bbc55f85311b76bd558fc"),
                ObjectId("608bbc55f85311b76bd558fd"),
                ObjectId("608bbc55f85311b76bd558fe")
        ]
}
> db.test.find().pretty()                                                             
{ "_id" : ObjectId("608bbc55f85311b76bd558fc"), "item" : "鉛筆", "price" : 2 }
{
        "_id" : ObjectId("608bbc55f85311b76bd558fd"),
        "item" : "鋼筆",
        "price" : 60
}
{
        "_id" : ObjectId("608bbc55f85311b76bd558fe"),
        "item" : "毛筆",
        "price" : 30
}
> db.test.remove({price:{$gt:3}})
WriteResult({ "nRemoved" : 2 })
> db.test.find().pretty()
{ "_id" : ObjectId("608bbc55f85311b76bd558fc"), "item" : "鉛筆", "price" : 2 }

3.洗掉滿足條件的單條檔案

命令：

> db.collection.remove({條件},{justOne:true})

實體：

> db.test.insertMany( [ {item:"鉛筆",price:2}, {item:"鋼筆",price:60},{item:"毛筆",price:30}] )
{
        "acknowledged" : true,
        "insertedIds" : [
                ObjectId("608bbdc9f85311b76bd558ff"),
                ObjectId("608bbdc9f85311b76bd55900"),
                ObjectId("608bbdc9f85311b76bd55901")
        ]
}
> db.test.find().pretty()                                                                
{ "_id" : ObjectId("608bbdc9f85311b76bd558ff"), "item" : "鉛筆", "price" : 2 }
{
        "_id" : ObjectId("608bbdc9f85311b76bd55900"),
        "item" : "鋼筆",
        "price" : 60
}
{
        "_id" : ObjectId("608bbdc9f85311b76bd55901"),
        "item" : "毛筆",
        "price" : 30
}
> db.test.remove({price:{$gt:3}},{justOne:true})
WriteResult({ "nRemoved" : 1 })
> db.test.find().pretty()
{ "_id" : ObjectId("608bbdc9f85311b76bd558ff"), "item" : "鉛筆", "price" : 2 }
{
        "_id" : ObjectId("608bbdc9f85311b76bd55901"),
        "item" : "毛筆",
        "price" : 30
}

4.delete

（1）deleteMany()

> db.books.find().pretty()
{
        "_id" : ObjectId("608bc487f85311b76bd5590b"),
        "name" : "<a cat story>",
        "price" : 20,
        "color" : "red"
}
{
        "_id" : ObjectId("608bc487f85311b76bd5590c"),
        "name" : "<crying birds story>",
        "price" : 20,
        "color" : "green"
}
{
        "_id" : ObjectId("608bc487f85311b76bd5590d"),
        "name" : "<big dogs story>",
        "price" : 25,
        "color" : "blue"
}
> db.books.deleteMany({price:20})
{ "acknowledged" : true, "deletedCount" : 2 }
> db.books.find().pretty()
{
        "_id" : ObjectId("608bc487f85311b76bd5590d"),
        "name" : "<big dogs story>",
        "price" : 25,
        "color" : "blue"
}

（2）deleteOne()

> db.books.find().pretty()
{
        "_id" : ObjectId("608bcdbff85311b76bd5590f"),
        "name" : "<a cat story>",
        "price" : 20,
        "color" : "red"
}
{
        "_id" : ObjectId("608bcdbff85311b76bd55910"),
        "name" : "<crying birds story>",
        "price" : 20,
        "color" : "green"
}
{
        "_id" : ObjectId("608bcdbff85311b76bd55911"),
        "name" : "<big dogs story>",
        "price" : 25,
        "color" : "blue"
}
> db.books.deleteOne({price:20})
{ "acknowledged" : true, "deletedCount" : 1 }
> db.books.find().pretty()
{
        "_id" : ObjectId("608bcdbff85311b76bd55910"),
        "name" : "<crying birds story>",
        "price" : 20,
        "color" : "green"
}
{
        "_id" : ObjectId("608bcdbff85311b76bd55911"),
        "name" : "<big dogs story>",
        "price" : 25,
        "color" : "blue"
}