MongoDB的CRUD操作(入门)
作者:互联网
MongoDB的简单介绍:
1:MongoDB是什么?
- mongodb是非关系数据库 但是是非关系数据库当中功能最丰富,最像关系数据库的
- MongoDB是一个基于分布式文件存储的数据库。
- 由C++语言编写。旨在为WEB应用提供可扩展的高性能数据存储解决方案。
2:MongoDB的三大特点:
3:先来介绍我们的插入语句吧
1:插入语句:
插入一条数据:
> db.jie.insert({name:"jie",age:18}) WriteResult({ "nInserted" : 1 })
可以使用:db.集合名.find()查看
> db.jie.find() { "_id" : ObjectId("6069ac8300fc7b062bb3ed94"), "name" : "jie", "age" : 18 }
这里id可以自己设置
可以指定id 不过最好不要指定
插入多条:
> db.jie.insert([{name:"luyunjie",age:18},{name:"jiebao",age:19}]) BulkWriteResult({ "writeErrors" : [ ], "writeConcernErrors" : [ ], "nInserted" : 2, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] })
mongodb也可以使用js语法 用for循环插入多条数据:
> for (var i=1;i<=10;i++){ db.jie1.insert({name: "jie"+i,age: i}) } WriteResult({ "nInserted" : 1 })
这里不为10是因为for循环是一条一条插入
然后只显示最后一条插入的数量 单用find()查看还是可以查看10条数据
> db.jie1.find()
{ "_id" : ObjectId("6069b34700fc7b062bb3ed97"), "name" : "jie1", "age" : 1 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed98"), "name" : "jie2", "age" : 2 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed99"), "name" : "jie3", "age" : 3 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed9a"), "name" : "jie4", "age" : 4 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed9b"), "name" : "jie5", "age" : 5 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed9c"), "name" : "jie6", "age" : 6 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed9d"), "name" : "jie7", "age" : 7 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed9e"), "name" : "jie8", "age" : 8 }
{ "_id" : ObjectId("6069b34700fc7b062bb3ed9f"), "name" : "jie9", "age" : 9 }
{ "_id" : ObjectId("6069b34700fc7b062bb3eda0"), "name" : "jie10", "age" : 10 }
2:查询语句
基本的运算符介绍:
出几个题目 配合查询语句来一一实现:
1:只查询字段name的值:
> db.jie1.find({},{name:1}) { "_id" : ObjectId("6069b34700fc7b062bb3ed97"), "name" : "jie1" } { "_id" : ObjectId("6069b34700fc7b062bb3ed98"), "name" : "jie2" } { "_id" : ObjectId("6069b34700fc7b062bb3ed99"), "name" : "jie3" } { "_id" : ObjectId("6069b34700fc7b062bb3ed9a"), "name" : "jie4" } { "_id" : ObjectId("6069b34700fc7b062bb3ed9b"), "name" : "jie5" } { "_id" : ObjectId("6069b34700fc7b062bb3ed9c"), "name" : "jie6" } { "_id" : ObjectId("6069b34700fc7b062bb3ed9d"), "name" : "jie7" } { "_id" : ObjectId("6069b34700fc7b062bb3ed9e"), "name" : "jie8" } { "_id" : ObjectId("6069b34700fc7b062bb3ed9f"), "name" : "jie9" } { "_id" : ObjectId("6069b34700fc7b062bb3eda0"), "name" : "jie10" }
无论查询什么 id都会一直在的
2:查询age大于5 小于8的所有数据:
> db.jie1.find({age:{$gte:5,$lte:8}}) { "_id" : ObjectId("6069b34700fc7b062bb3ed9b"), "name" : "jie5", "age" : 5 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9c"), "name" : "jie6", "age" : 6 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9d"), "name" : "jie7", "age" : 7 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9e"), "name" : "jie8", "age" : 8 }
运用我们的运算符来达到效果 运算符的语法是
db.集合名.find(
键:{运算符:值}
)
3:查询age为1,4, 5, 9 的所有数据:
> db.jie1.find({age:{$in:[1,4,5,9]}}) { "_id" : ObjectId("6069b34700fc7b062bb3ed97"), "name" : "jie1", "age" : 1 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9a"), "name" : "jie4", "age" : 4 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9b"), "name" : "jie5", "age" : 5 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9f"), "name" : "jie9", "age" : 9 }
运用运算符达到效果
上面用我们的小案列来简单介绍一下mongodb的查询以后会慢慢更新的
3:修改(更新)语句:
修改器的基本介绍:
如果不用修改器来修改数据 则是替换:
列子:
> db.jie.update({name:"jie"},{name:"xiaojie"}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 }) > db.jie.find() { "_id" : ObjectId("6069ac8300fc7b062bb3ed94"), "name" : "xiaojie" } { "_id" : ObjectId("6069ad8700fc7b062bb3ed95"), "name" : "luyunjie", "age" : 18 } { "_id" : ObjectId("6069ad8700fc7b062bb3ed96"), "name" : "jiebao", "age" : 19 } >
到达的是替换的效果
我们继续举列子来讲解:
1:修改name为luyunjie的字段 把luyunjie改为xiaojiejie其他不变:
> db.jie.update({name:"luyunjie"},{$set:{name:"xiaojiejie"}}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 }) > db.jie.find() { "_id" : ObjectId("6069ac8300fc7b062bb3ed94"), "name" : "xiaojie" } { "_id" : ObjectId("6069ad8700fc7b062bb3ed95"), "name" : "xiaojiejie", "age" : 18 } { "_id" : ObjectId("6069ad8700fc7b062bb3ed96"), "name" : "jiebao", "age" : 19 } 修改成功 运用修改器 修改器语法: db.集合名.updata( {修改的值}, {修改器:{修改的值} })
2:给age为20的数据递加或递减5:
递增:
> db.jie.update({age:20},{$inc:{age:5}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.jie.find()
{ "_id" : ObjectId("6069ac8300fc7b062bb3ed94"), "name" : "xiaojie" }
{ "_id" : ObjectId("6069ad8700fc7b062bb3ed95"), "name" : "xiaojiejie", "age" : 25 }
{ "_id" : ObjectId("6069ad8700fc7b062bb3ed96"), "name" : "jiebao", "age" : 19 }
递减:
> db.jie.update({age:18},{$inc:{age:-5}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.jie.find()
{ "_id" : ObjectId("6069ac8300fc7b062bb3ed94"), "name" : "xiaojie" }
{ "_id" : ObjectId("6069ad8700fc7b062bb3ed95"), "name" : "xiaojiejie", "age" : 20 }
{ "_id" : ObjectId("6069ad8700fc7b062bb3ed96"), "name" : "jiebao", "age" : 19 }
>
3:练习为修改器为修改多个值
题目:把name里面的数据改为小杰,age数据递增20,sex字段删除,dta字段改为bianhao;
准备数据:
> db.xiaojie.insert({name:"jie",age:20,sex:"boy",dta:"123"}) WriteResult({ "nInserted" : 1 }) > db.xiaojie.find() { "_id" : ObjectId("6069c59800fc7b062bb3eda1"), "name" : "jie", "age" : 20, "sex" : "boy", "dta" : "123" }
题目答案:
> db.xiaojie.update({name:"jie"},{$set:{name:"小杰"},$inc:{age:20},$rename:{dta:"bianhao"},$unset:{sex:true}}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 }) > db.xiaojie.find() { "_id" : ObjectId("6069c59800fc7b062bb3eda1"), "name" : "小杰", "age" : 40, "bianhao" : "123" }
这里有几个点 多条语句的写法如上 db.集合名.update
({修改字段:字段值}, {
修改器:{},
修改器:{},
修改器:{},
修改器:{}
})
4:删除语句:
删除语法是:
db.集合名.remove({条件},是否删除一条)
1:删除一条数据:
> db.jie1.remove({},true) WriteResult({ "nRemoved" : 1 }) > db.jie1.find() { "_id" : ObjectId("6069b34700fc7b062bb3ed98"), "name" : "jie2", "age" : 2 } { "_id" : ObjectId("6069b34700fc7b062bb3ed99"), "name" : "jie3", "age" : 3 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9a"), "name" : "jie4", "age" : 4 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9b"), "name" : "jie5", "age" : 5 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9c"), "name" : "jie6", "age" : 6 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9d"), "name" : "jie7", "age" : 7 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9e"), "name" : "jie8", "age" : 8 } { "_id" : ObjectId("6069b34700fc7b062bb3ed9f"), "name" : "jie9", "age" : 9 } { "_id" : ObjectId("6069b34700fc7b062bb3eda0"), "name" : "jie10", "age" : 10 }
2:删除全部数据:
> db.jie1.remove({}) WriteResult({ "nRemoved" : 9 })
简单介绍了一下MongoDB的CRUD操作 这篇博客会慢慢完善成MongoDB笔记 加油一起努力!
标签:jie,入门,ObjectId,MongoDB,age,CRUD,db,id,name 来源: https://www.cnblogs.com/yunjie0930/p/14616995.html