mongodb update

db.集合名称.update({query},{update},upsert, multi})
过滤条件;
修改内容;
是否插入数据(若不存在),默认false;
是否只查询条件的第一条,默认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 }

更新/添加指定条件的某键;
$set

> 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 }

删除指定条件的某键
$unset

> 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" }

在原来的基础上的运算
$inc

> 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 }

数组

push:当数据中不存在键时，创建数组类型的键并插入该值;如果存在该键，并且该键是数组类型时，则在此数>组类型的数据上追加;如果存在该键，并且该键不是数组类型时，会报错。pushAll:批量往数组中追加
$addToSet:数组中有该值时不追加，没有该值时追加

> 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:删除数组的第一个或最后一个元素，值为−1时是删除第一个元素，值为1时是删除最后一个元素。pull:删除数组中的某一个指定的数值
$pullAll:删除数组中多个指定的数值

> 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" : [ ] }

id不能转换

> 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 }