MongoDB的安装与基本使用

来源：互联网发布：vehicleblackbox淘宝编辑：程序博客网时间：2024/05/16 23:45

Mongodb的安装：

vi /etc/selinux/config
Modify:SELINUX=disabled
service iptables stop
yum -y install wget
wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel62-3.0.6.tgz
tar -zxvf mongodb-linux-x86_64-rhel62-3.4.2.tgz
mv mongodb-linux-x86_64-rhel62-3.4.2 /usr/local/mongodb
cd /usr/local/mongodb/bin
mkdir -p /data/db /data/logs
touch /data/logs/mongodb.log
./mongod --dbpath=/data/db -fork --logpath=/data/logs/mongodb.log #-fork 表示后台运行
export PATH=/usr/local/mongodb/bin:$PATH
mongo 进入mongodb，可以使用CTRL+D来进行退出

Mongodb的基本使用：

db.version() 查看当前mongodb数据库版本

3.0.6

show dbs 查看当前的所有数据库

   > show dbs
   local 0.078GB
   gogo   0.078GB

db 查看当前所在数据库的位置，即位于哪个数据库

> db
gogo

use gogo 切换到数据库gogo

show collections 查看当前数据库内的集合

   > show collections
   system.indexes
   user

db.user.insert({"name":"zhangsan","age":"22","height":"1.72","weight":"60kg"}) 插入文档
> db.user.insert({"name":"zhangsan","age":"22","height":"1.72","weight":"60kg"})
WriteResult({ "nInserted" : 1 })

db.user.find() 查看当前user集合下的所有文档

db.user.remove() 删除当前user集合下的所有文档

> db.user.remove({})
WriteResult({ "nRemoved" : 3 })

db.user.stats() 查看当前user集合的状态信息

   > db.user.stats()
   {
            "ns" : "mall.user",
            "count" : 3,
            "size" : 336,
            "avgObjSize" : 112,
            "numExtents" : 1,
            "storageSize" : 8192,
            "lastExtentSize" : 8192,
            "paddingFactor" : 1,
            "paddingFactorNote" : "paddingFactor is unused and unmaintained in 3.0. It remains hard coded to 1.0 for compatibility only.",
            "userFlags" : 1,
            "capped" : false,
            "nindexes" : 1,
            "totalIndexSize" : 8176,
            "indexSizes" : {
                    "_id_" : 8176
            },
            "ok" : 1
   }

db.user.find({"age":"22"}) 可以凭单个字段进行检索

   > db.user.find()
       { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "22", "height" : "1.72", "weight" : "60kg" }
       { "_id" : ObjectId("58d13e8379a177687c20accc"), "name" : "lisi", "age" : "25", "height" : "1.60", "weight" : "50kg" }
       { "_id" : ObjectId("58d13e8b79a177687c20accd"), "name" : "hunagwu", "age" : "27", "height" : "1.66", "weight" : "65kg" }
       { "_id" : ObjectId("58d1488579a177687c20acce"), "name" : "xingliu", "age" : "22", "height" : "1.72", "weight" : "60kg" }
   > db.user.find({"age":"22"})
       { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "22", "height" : "1.72", "weight" : "60kg" }
       { "_id" : ObjectId("58d1488579a177687c20acce"), "name" : "xingliu", "age" : "22", "height" : "1.72", "weight" : "60kg" }

db.user.save

   1.文档存在就更新，不存在就新建
   > db.user.save({"name":"binbin"})
   WriteResult({ "nInserted" : 1 })
   db.user.find({"name":"binbin"})
   { "_id" : ObjectId("58d15f8879a177687c20accf"), "name" : "binbin" }

db.user.update

1.整体替换文档中的内容：

   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "22", "height" : "1.72", "weight" : "60kg" }
   > db.user.update({"name":"zhangsan"},{"name":"zhangsan","age":"26"})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
   可以通过下面看到最终zhangsan的年龄被更改成了26，而且其后面的字段被删除。所以这是个整体型替换。
   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26" }

2.找不到就新增：

   那如果找不到该怎么办呢？比如里面没有zhangsan这个人。那么就需要，让其在查找的时候，找不到就新增，找到就全部替换。(需要在后面添加true)
   > db.user.update({"name":"wanghui"},{"name":"wanghui","age":"18","sex":"girl"},true)
   WriteResult({
    "nMatched" : 0,
    "nUpserted" : 1,
    "nModified" : 0,
    "_id" : ObjectId("58d15323ecd08bc8f1114c90")
   })

3.局部替换文档中的内容：

   只更改部分字段，保留其他字段：（使用$set:）此为原来的数据：
   > db.user.find({"name":"lisi"})
   { "_id" : ObjectId("58d13e8379a177687c20accc"), "name" : "lisi", "age" : "25", "height" : "1.60", "weight" : "50kg" }
   更改weight的字段：
   > db.user.update({"name":"lisi"},{$set:{"weight":"55kg"}})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.user.find({"name":"lisi"})
   { "_id" : ObjectId("58d13e8379a177687c20accc"), "name" : "lisi", "age" : "25", "height" : "1.60", "weight" : "55kg" }

4.$set:找不到就新增：

   如果找不到要修改的字段，则新增这个字段：
   > db.user.update({"name":"lisi"},{$set:{"sex":"man"}})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
   最后可以看到weight变成了55kg，且新增的字段sex为man：
   > db.user.find({"name":"lisi"})
   { "_id" : ObjectId("58d13e8379a177687c20accc"), "name" : "lisi", "age" : "25", "height" : "1.60", "weight" : "55kg", "sex" : "man" }

5.$unset:删除某一个字段:

   > db.user.find({"name":"lisi"})
   { "_id" : ObjectId("58d13e8379a177687c20accc"), "name" : "lisi", "age" : "25", "height" : "1.60", "weight" : "55kg", "sex" : "man" }
   > db.user.update({"name":"lisi"},{$unset:{"weight":"55kg"}})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
   > db.user.find({"name":"lisi"})
   { "_id" : ObjectId("58d13e8379a177687c20accc"), "name" : "lisi", "age" : "25", "height" : "1.60", "sex" : "man" }

6.$set新建数组，并在数组的末尾新增$push一个元素

   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26" }
   > db.user.update({"name":"zhangsan"},{$set:{group:[3,4]}})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26", "group" : [ 3, 4 ] }
   > db.user.update({"name":"zhangsan"},{$push:{group:5}})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26", "group" : [ 3, 4, 5 ] }

7.通过使用$push和$each一次推送多个值

   > db.user.update({"name":"zhangsan"},{$push:{group:{$each:[5,6,7,8]}}})
   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26", "group" : [ 3, 4, 5, 5, 6, 7, 8 ] }

8.替换数组内的元素

   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26", "group" : [ 3, 4, 5, 5, 6, 7, 8 ] }
   > db.user.update({"name":"zhangsan"},{$set:{"group.1":1}})
   WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
   > db.user.find({"name":"zhangsan"})
   { "_id" : ObjectId("58d13e7d79a177687c20accb"), "name" : "zhangsan", "age" : "26", "group" : [ 3, 1, 5, 5, 6, 7, 8 ] }

9.查询更新文档：

   > db.runCommand({"getLastError":1})
   {
            "connectionId" : 3,
            "n" : 0,
            "syncMillis" : 0,
            "writtenTo" : null,
            "err" : null,
            "ok" : 1
   }
   “n”表示更新文档的数量

参考文献：

http://blog.csdn.net/xiaoxing598/article/details/54233044#t11

0 0