mongodb 批次更新 操作文檔的數組鍵

標籤：mongodb 運算元組元素

persons文檔的資料如下:

> db.persons.find()
{ "_id" : 2, "name" : 2 }
{ "_id" : 3, "name" : 3 }

> db.persons.update({_id:4},{_id:4,name:4})
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
> db.persons.find()
{ "_id" : 2, "name" : 2 }
{ "_id" : 3, "name" : 3 }

做完update操作，依然看不到_id:4的記錄，因為update方法需要一個true指標，才會對查詢不到的記錄進行insert操作：

> db.persons.update({_id:4},{_id:4,name:4},true)
WriteResult({ "nMatched" : 0, "nUpserted" : 1, "nModified" : 0, "_id" : 4 })
> db.persons.find()
{ "_id" : 2, "name" : 2 }
{ "_id" : 3, "name" : 3 }
{ "_id" : 4, "name" : 4 }

現有需求，將persons文檔中的name為"3"的改成"33"

> db.persons.update({name:"3"},{$set:{name:"33"}},false,true)

false含義:若查不到name:"33"的鍵值對，則不執行插入操作，true含義:表示是批次更新

為persons增加age:"88"屬性

> db.persons.update({name:"4"},{$set:{age:"88"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4", "age" : "88" }

將age加2

> db.persons.update({name:"4"},{$inc:{age:2}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4", "age" : 90 }

將age屬性拿走：

> db.persons.update({age:90},{$unset:{age:1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }

給persons文檔增加一條記錄，_id為5

> db.persons.insert({_id:5,name:5,books:[]})
WriteResult({ "nInserted" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "name" : 5, "books" : [ ] }

給books數組增加一個元素:"js"和"extjs4.0"

> db.persons.update({_id:5},{$push:{books:"js"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "name" : 5, "books" : [ "js" ] }

> db.persons.update({_id:5},{$push:{books:"extjs4.0"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "name" : 5, "books" : [ "js", "extjs4.0" ] }

建立一個新的classes數組:

> db.persons.update({_id:5},{$push:{classes:"01class"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "name" : 5, "books" : [ "js", "extjs4.0" ], "classes" : [ "01class"
 ] }

為calsses數組一次增加幾個元素:

> db.persons.update({_id:5},{$pushAll:{classes:["02class","03class","04class"]}}
)
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "name" : 5, "books" : [ "js", "extjs4.0" ], "classes" : [ "01class"
, "02class", "03class", "04class" ] }

刪除_id是5的記錄,並建立一個新的_id是5的記錄,使用$addToSet,此命令會檢查要添加的元素在數組裡面是不是存在，存在就不會再添加，否則會添加:

> db.persons.remove({_id:5})
WriteResult({ "nRemoved" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
> db.persons.insert({_id:5,books:["js"]})
WriteResult({ "nInserted" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "js" ] }
> db.persons.update({_id:5},{$addToSet:{books:"js"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "js" ] }
> db.persons.update({_id:5},{$addToSet:{books:"java"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "js", "java" ] }
> db.persons.update({_id:5},{$addToSet:{books:"mongo"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "js", "java", "mongo" ] }

刪除books數組的第一個元素:"js"，使用$pop命令:

> db.persons.update({_id:5},{$pop:{books:-1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "java", "mongo" ] }
> db.persons.update({_id:5},{$pop:{books:1}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "java" ] }

-1代表第一個元素，1代表最後一個元素

也可以使用pull命令一次刪除一個指定的元素:

> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "java", "mongo", "js" ] }
> db.persons.update({_id:5},{$pull:{books:"js"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ "java", "mongo" ] }

$pullAll命令可以一次指定多個要刪除的元素:

> db.persons.update({_id:5},{$pullAll:{books:["java","mongo"]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ ] }

建立一條新的記錄_id為6:

> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ ] }
{ "_id" : 6, "books" : [ { "type" : "js", "name" : "extjs4.0" }, { "type" : "db"
, "name" : "mongodb" }, { "type" : "js", "name" : "jquery" } ] }

為type是js的books元素添加pens:"too long"屬性，使用.符號一定使用雙引號引用

> db.persons.update({"books.type":"js"},{$set:{"books.$.author":"tom"}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4, "name" : "4" }
{ "_id" : 5, "books" : [ ] }
{ "_id" : 6, "books" : [ { "type" : "js", "name" : "extjs4.0", "author" : "tom"
}, { "type" : "db", "name" : "mongodb" }]
 }

 db.persons.update({"books.type":"js"},{$set:{"books.$.pens":"too long"}})

判斷數組元素執行插入操作，重複的元素不會被插入第二次:

> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4 }
{ "_id" : 5, "books" : [ "js" ] }

> db.persons.update({_id:5},{$addToSet:{books:{$each:["js","db","java"]}}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.persons.find()
{ "_id" : 2, "name" : "33" }
{ "_id" : 3, "name" : "33" }
{ "_id" : 4 }
{ "_id" : 5, "books" : [ "js", "db", "java" ] }

mongodb 批次更新 操作文檔的數組鍵