MongoDB
MongoDB 是一個開源的文檔數據庫，并領先的 NoSQL 數據庫。 MongoDB 是由 c++語言編寫。
文檔
文檔是一組鍵 - 值對。文件動態模式。動態模式是指，在相同集合中的文檔不需要具有相同的字段或結構組的公共字段的集合的文檔，可以容納不同類型的數據。
db.集合名稱.update({query},{update},upsert, multi})
query:過濾條件
update:修改內容
upsert：如果不存在查詢條件查出的記錄，是否插入一條數據，默認是false
multi：是否只修改查詢條件查出的第一條記錄，默認是false
> db.student.update({_id:1}, {name:"zhang"})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhang" }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 } 把整條數據都修改了，如果修改內容中沒有設置age字段，則以前的age也取消了，數據全部修改
局部修改
$set:如果存在鍵則修改，如果不存在鍵則添加
> db.student.update({_id: 1},{$set:{name:"zhangsan", age: 26}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 } id重復時無法修改
> db.student.update({_id:1},{_id:0, name:"zhangsanzhangsan"})WriteResult({"nMatched" : 0,"nUpserted" : 0,"nModified" : 0,"writeError" : {"code" : 16837,"errmsg" : "The _id field cannot be changed from {_id: 1.0} to {_id: 0.0}."}})> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 } 第三個參數默認為false，如果查不到數據false時不執行任何操作，true時往數據庫里新插入一條數據
> db.student.update({_id:7},{_id:7, name: "songjiu", age:32})WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })> db.student.update({_id:7},{_id:7, name: "songjiu"}, true)WriteResult({ "nMatched" : 0, "nUpserted" : 1, "nModified" : 0, "_id" : 7 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "age" : 32 } 第四個參數默認為false，false時表示只修改查詢到的第一條數據，true時表示修改查詢到的所有數據
> db.student.update({age:32}, {$set:{age:33}}, false, false)WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 33 }{ "_id" : 7, "name" : "songjiu", "age" : 32 }> db.student.update({age:33}, {$set:{age:32}}, false, true)WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 32 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "age" : 32 }> db.student.update({age:32}, {$set:{age:33}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "age" : 32 } $inc:在原來的基礎上加多少
> db.student.update({_id:7}, {$inc:{age:-1}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "age" : 31 } $unset:去掉某個鍵
> db.student.update({_id:7},{$unset:{age:1}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu" } 針對數組類型的操作
$push:當數據中不存在鍵時，創建數組類型的鍵并插入該值;如果存在該鍵，并且該鍵是數組類型時，則在此數組類型的數據上追加;如果存在該鍵，并且該鍵不是數組類型時，會報錯。
$pushAll:批量往數組中追加
$addToSet:數組中有該值時不追加，沒有該值時追加
> db.student.update({_id: 7},{$push:{skill:"java"}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "java" ] }> db.student.update({_id: 7},{$push:{skill:"mongodb"}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb" ] }> db.student.update({_id: 7},{$push:{name:"111"}})WriteResult({"nMatched" : 0,"nUpserted" : 0,"nModified" : 0,"writeError" : {"code" : 16837,"errmsg" : "The field 'name' must be an array but is of type String in document {_id: 7.0}"}})> db.student.update({_id: 7},{$pushAll:{skill:["js","C++","java"]}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb", "js", "C++", "java" ] }> db.student.update({_id:7},{$addToSet:{skill:"mongodb"}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb", "js", "C++", "java" ] } $pop:刪除數組的第一個或最后一個元素，值為-1時是刪除第一個元素，值為1時是刪除最后一個元素。
$pull:刪除數組中的某一個指定的數值
$pullAll:刪除數組中多個指定的數值
> db.student.update({_id:7},{$pop:{skill:1}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "java", "mongodb", "js", "C++" ] }> db.student.update({_id:7},{$pop:{skill:-1}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "mongodb", "js", "C++" ] }> db.student.update({_id:7},{$pull:{skill:"js"}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "mongodb", "C++" ] }> db.student.update({_id:7},{$pullAll:{skill:["js"]}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ "mongodb", "C++" ] }> db.student.update({_id:7},{$pullAll:{skill:["mongodb","C++"]}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.student.find(){ "_id" : 1, "name" : "zhangsan", "age" : 26 }{ "_id" : 2, "name" : "lisi", "age" : 27 }{ "_id" : 3, "name" : "wangwu", "age" : 30 }{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }{ "_id" : 5, "name" : "qianliu", "age" : 33 }{ "_id" : 6, "name" : "sunba", "age" : 32 }{ "_id" : 7, "name" : "songjiu", "skill" : [ ] }新聞熱點
疑難解答
