簡單命令 - 簡書

MongoDB Shell入門例子

db命令【創(chuàng)建切換數(shù)據(jù)庫】

db是指您當(dāng)前的數(shù)據(jù)庫
要切換數(shù)據(jù)庫业簿，請鍵入详羡。use <db>examples
切換之前作儿，無需創(chuàng)建數(shù)據(jù)庫。當(dāng)您第一次在數(shù)據(jù)庫中存儲數(shù)據(jù)時(shí)（例如在數(shù)據(jù)庫中創(chuàng)建第一個集合）雏吭，MongoDB會創(chuàng)建數(shù)據(jù)庫狡耻。

> db
test
> use mydb
switched to db mydb
> db
mydb

插入表數(shù)據(jù)

集合類似于關(guān)系數(shù)據(jù)庫中的表。如果不存在集合挑胸，則在您第一次為該集合存儲數(shù)據(jù)時(shí)痒筒，MongoDB會創(chuàng)建該集合。
以下示例使用該 db.collection.insertMany()方法將新文檔插入到inventory 集合中

> db.inventory.insertMany([
...    { item: "journal", qty: 25, status: "A", size: { h: 14, w: 21, uom: "cm" }, tags: [ "blank", "red" ] },
...    { item: "notebook", qty: 50, status: "A", size: { h: 8.5, w: 11, uom: "in" }, tags: [ "red", "blank" ] },
...    { item: "paper", qty: 10, status: "D", size: { h: 8.5, w: 11, uom: "in" }, tags: [ "red", "blank", "plain" ] },
...    { item: "planner", qty: 0, status: "D", size: { h: 22.85, w: 30, uom: "cm" }, tags: [ "blank", "red" ] },
...    { item: "postcard", qty: 45, status: "A", size: { h: 10, w: 15.25, uom: "cm" }, tags: [ "blue" ] }
... ]);
{
    "acknowledged" : true,
    "insertedIds" : [
        ObjectId("5ebe42508073754f2e3f11b3"),
        ObjectId("5ebe42508073754f2e3f11b4"),
        ObjectId("5ebe42508073754f2e3f11b5"),
        ObjectId("5ebe42508073754f2e3f11b6"),
        ObjectId("5ebe42508073754f2e3f11b7")
    ]
}

查詢文檔

查詢所有
db.inventory.find({})
db.inventory.find({}).pretty()
要格式化結(jié)果茬贵，請將追加.pretty()到 find操作：

> db.inventory.find({})
{ "_id" : ObjectId("5ebe42508073754f2e3f11b3"), "item" : "journal", "qty" : 25, "status" : "A", "size" : { "h" : 14, "w" : 21, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b4"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b5"), "item" : "paper", "qty" : 10, "status" : "D", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank", "plain" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b6"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b7"), "item" : "postcard", "qty" : 45, "status" : "A", "size" : { "h" : 10, "w" : 15.25, "uom" : "cm" }, "tags" : [ "blue" ] }
> db.inventory.find({}).pretty()
{
    "_id" : ObjectId("5ebe42508073754f2e3f11b3"),
    "item" : "journal",
    "qty" : 25,
    "status" : "A",
    "size" : {
        "h" : 14,
        "w" : 21,
        "uom" : "cm"
    },
    "tags" : [
        "blank",
        "red"
    ]
}
{
    "_id" : ObjectId("5ebe42508073754f2e3f11b4"),
    "item" : "notebook",
    "qty" : 50,
    "status" : "A",
    "size" : {
        "h" : 8.5,
        "w" : 11,
        "uom" : "in"
    },
    "tags" : [
        "red",
        "blank"
    ]
}
{
    "_id" : ObjectId("5ebe42508073754f2e3f11b5"),
    "item" : "paper",
    "qty" : 10,
    "status" : "D",
    "size" : {
        "h" : 8.5,
        "w" : 11,
        "uom" : "in"
    },
    "tags" : [
        "red",
        "blank",
        "plain"
    ]
}
{
    "_id" : ObjectId("5ebe42508073754f2e3f11b6"),
    "item" : "planner",
    "qty" : 0,
    "status" : "D",
    "size" : {
        "h" : 22.85,
        "w" : 30,
        "uom" : "cm"
    },
    "tags" : [
        "blank",
        "red"
    ]
}
{
    "_id" : ObjectId("5ebe42508073754f2e3f11b7"),
    "item" : "postcard",
    "qty" : 45,
    "status" : "A",
    "size" : {
        "h" : 10,
        "w" : 15.25,
        "uom" : "cm"
    },
    "tags" : [
        "blue"
    ]
}
>

條件查找

對于相等匹配（即<field>equals <value>）簿透，在查詢過濾器文檔中指定并傳遞給該方法。<field>:<value>db.collection.find()

多條件查找

> db.inventory.find( { qty: 0, status: "D" } );
{ "_id" : ObjectId("5ebe42508073754f2e3f11b6"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }

嵌套條件查找

> db.inventory.find( { "size.uom": "in" } )
{ "_id" : ObjectId("5ebe42508073754f2e3f11b4"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b5"), "item" : "paper", "qty" : 10, "status" : "D", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank", "plain" ] }

-- 嵌入式文檔上的相等匹配要求完全匹配闷沥，包括字段順序萎战。
> db.inventory.find( { size: { h: 14, w: 21, uom: "cm" } } )
{ "_id" : ObjectId("5ebe42508073754f2e3f11b3"), "item" : "journal", "qty" : 25, "status" : "A", "size" : { "h" : 14, "w" : 21, "uom" : "cm" }, "tags" : [ "blank", "red" ] }

數(shù)組查找
其中tags數(shù)組包含"red"為其元素之一，如果該tags字段是字符串而不是數(shù)組舆逃，則查詢只是一個相等匹配蚂维。

> db.inventory.find( { tags: "red" } )
{ "_id" : ObjectId("5ebe42508073754f2e3f11b3"), "item" : "journal", "qty" : 25, "status" : "A", "size" : { "h" : 14, "w" : 21, "uom" : "cm" }, "tags" : [ "blank", "red" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b4"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b5"), "item" : "paper", "qty" : 10, "status" : "D", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank", "plain" ] }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b6"), "item" : "planner", "qty" : 0, "status" : "D", "size" : { "h" : 22.85, "w" : 30, "uom" : "cm" }, "tags" : [ "blank", "red" ] }

-- 以返回該tags字段與指定數(shù)組完全匹配的文檔戳粒，包括順序
> db.inventory.find( { tags: [ "red", "blank" ] } )
{ "_id" : ObjectId("5ebe42508073754f2e3f11b4"), "item" : "notebook", "qty" : 50, "status" : "A", "size" : { "h" : 8.5, "w" : 11, "uom" : "in" }, "tags" : [ "red", "blank" ] }

要返回的字段，默認(rèn)返回所有

要指定要返回的字段虫啥，請將投影文檔傳遞給該方法蔚约。在投影文檔中，指定：db.collection.find(<query document>, <projection document>)

<field>: 1 在返回的文檔中包含一個字段
<field>: 0 在返回的文檔中排除字段
您不必指定_id字段即可返回該字段涂籽。默認(rèn)情況下返回苹祟。要排除該字段，請0在投影文檔中將其設(shè)置為评雌。

> db.inventory.find( { }, { item: 1, status: 1 } );
{ "_id" : ObjectId("5ebe42508073754f2e3f11b3"), "item" : "journal", "status" : "A" }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b4"), "item" : "notebook", "status" : "A" }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b5"), "item" : "paper", "status" : "D" }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b6"), "item" : "planner", "status" : "D" }
{ "_id" : ObjectId("5ebe42508073754f2e3f11b7"), "item" : "postcard", "status" : "A" }

-- 排除id字段
> db.inventory.find( {}, { _id: 0, item: 1, status: 1 } );
{ "item" : "journal", "status" : "A" }
{ "item" : "notebook", "status" : "A" }
{ "item" : "paper", "status" : "D" }
{ "item" : "planner", "status" : "D" }
{ "item" : "postcard", "status" : "A" }