除了查询条件，还可以使用修改器对文档进行更新。
1. $inc
> db.tianyc03.find()
{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 11 }> db.tianyc03.update({name:'xtt',age:11},{'$inc':{age:5}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "name" : "xtt", "age" : 16 }#$inc还可以添加列。
> db.tianyc04.find()
{ "_id" : ObjectId("510c83ad13d7e50c2281b048"), "wc" : 1 }> db.tianyc04.update({wc:1},{$inc:{score:50}})> db.tianyc04.find(){ "_id" : ObjectId("510c83ad13d7e50c2281b048"), "score" : 50, "wc" : 1 }>2. $set
用来指定一个键的值，若该键不存在，则创建。如果需要删除该键，使用$unset。
#新增加列sex
> db.tianyc03.update({name:'xtt',age:16},{$set:{sex:'m'}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "name" : "xtt", "sex" : "m" }#修改列sex> db.tianyc03.update({name:'xtt',age:16},{$set:{sex:'male'}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "name" : "xtt", "sex" : "male" }#改变列sex数据类型> db.tianyc03.update({name:'xtt',age:16},{$set:{sex:1}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "name" : "xtt", "sex" : 1 }#删除列sex> db.tianyc03.update({name:'xtt',age:16},{$unset:{sex:1}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "name" : "xtt" }3. $push
用来增加数组。若没有改列，则会自动增加。
> db.tianyc03.find()
{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "name" : "xtt" }> db.tianyc03.update({'name':'xtt'},{$push:{companies:'neu'}})
> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu" ], "name" : "xtt" }> db.tianyc03.update({'name':'xtt'},{$push:{companies:'alibaba'}})
> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu", "alibaba" ], "name" : "xtt" }4. $addToSet
#push操作不会检查数组中元素是否重复，如果需要将不重复的数据加入数组，需要使用$addToSet
> db.tianyc03.update({'name':'xtt'},{$addToSet:{companies:'alibaba'}})
> db.tianyc03.find()
{ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu", "alibaba", "alibaba" ], "name" : "xtt" }> db.tianyc03.update({'name':'xtt'},{$addToSet:{companies:'congxing'}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu", "alibaba", "alibaba", "congxing" ], "name" : "xtt" }> db.tianyc03.update({'name':'xtt'},{$addToSet:{companies:'congxing'}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu", "alibaba", "alibaba", "congxing" ], "name" : "xtt" }>5. $pop
通过$pop可以从数组中移除数据。此时数据被看成是一个队列。使用{$pop:{key:1}}将从队列末尾移除元素，使用{$pop:{key:-1}}将从队列开头移除元素。
> db.tianyc03.update({'name':'xtt'},{$addToSet:{companies:['c1','c2']}})
> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu", "alibaba", "alibaba", "congxing", [ "c1", "c2" ] ], "name" : "xtt" }> db.tianyc03.update({'name':'xtt'},{$pop:{companies:1}})
> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "neu", "alibaba", "alibaba", "congxing" ], "name" : "xtt" }>> db.tianyc03.update({'name':'xtt'},{$pop:{companies:-1}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "alibaba", "alibaba", "congxing" ], "name" : "xtt" }>6. $pull
除了 $pop，也可以使用 $pull 来删除数组中的元素，此时可以根据元素值进行匹配，将匹配上的元素全部删除。
> db.tianyc03.update({'name':'xtt'},{$addToSet:{companies:'teletek'}})
> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "alibaba", "alibaba", "congxing", "teletek" ], "name" : "xtt" }> db.tianyc03.update({},{$pull:{companies:'congxing'}})> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "alibaba", "alibaba", "teletek" ], "name" : "xtt" }> db.tianyc03.update({},{$pull:{companies:'alibaba'}})
> db.tianyc03.find(){ "_id" : ObjectId("50ea6b6f12729d90ce6e341b"), "age" : 16, "companies" : [ "teletek" ], "name" : "xtt" }>