MongoDB的CRUD操作讲解-3-update&remove

//把item等与MNO2的记录，更新category，details属性，并把lastModified属性更新为当前时间
db.inventory.update(
    { item: "MNO2" },
    {
        $set: {
        category: "apparel",
        details: { model: "14Q3", manufacturer: "XYZ Company" }
        },
        $currentDate: { lastModified: true }
    }
)
//更新嵌套属性
db.inventory.update(
    { item: "ABC1" },
    { $set: { "details.model": "14Q2" } }
)
//更新多条文档
db.inventory.update(
    { category: "clothing" },
    {
        $set: { category: "apparel" },
        $currentDate: { lastModified: true }
    },
    { multi: true }
)
//新item记录替换旧的，新记录包含旧id和新记录的属性
db.inventory.update(
    { item: "BE10" },
    {
        item: "BE05",
        stock: [ { size: "S", qty: 20 }, { size: "M", qty: 5 } ],
        category: "apparel"
    }
)
//如果匹配就替换，不匹配就新插入一条文档
db.inventory.update(
    { item: "TBD1" },
    {
        item: "TBD1",
        details: { "model" : "14Q4", "manufacturer" : "ABC Company" },
        stock: [ { "size" : "S", "qty" : 25 } ],
        category: "houseware"
    },
    { upsert: true }
)
//如果匹配就做update操作，没有匹配就新插入一条文档
db.inventory.update(
    { item: "TBD2" },
    {
        $set: {
        details: { "model" : "14Q3", "manufacturer" : "IJK Co." },
        category: "houseware"
    }
    },
    { upsert: true }
)

//删除集合内所有文档，但不删除索引
db.inventory.remove({})
//集合索引同时删除
db.inventory.drop()
//删除type属性匹配的文档
db.inventory.remove( { type : "food" } )