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SQL Terms/Concepts |
MongoDB Terms/Concepts |
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database |
database |
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table |
Collection（集合） |
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row |
document（文档） |
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column |
Key（键） |
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Value |
Value（值） |
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index |
index |
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table joins |
embedded documents and linking |
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primary key |
primary key |
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Specify any unique column or column combination as primary key. |
In MongoDB, the primary key is automatically set to the _id field. |
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aggregation (e.g. group by) |
aggregation pipeline |
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Help |
查看帮助（mongodb 中注意大小写） |
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db.help() |
help on db methods |
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db.mycoll.help() |
help on collection methods |
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sh.help() |
sharding helpers |
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rs.help() |
replica set helpers |
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help admin |
administrative help |
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help connect |
connecting to a db help |
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help keys |
key shortcuts |
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help misc |
misc things to know |
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help mr |
mapreduce |
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show dbs |
show database names |
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show collections |
show collections in current database |
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show users |
show users in current database |
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show profile |
show most recent system.profile entries with time >= 1ms |
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show logs |
show the accessible logger names |
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show log [name] |
prints out the last segment of log in memory, ‘global‘ is default |
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use <db_name> |
set current database |
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db.foo.find() |
list objects in collection foo |
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db.foo.find( { a : 1 } ) |
list objects in foo where a == 1 |
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it |
result of the last line evaluated; use to further iterate |
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DBQuery.shellBatchSize = x |
set default number of items to display on shell |
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exit |
quit the mongo shell |
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数据库 |
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show dbs |
查看所有数据库 |
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use mydb |
设置为当前数据库 |
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db |
查看当前数据库名称 |
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db.createCollection("tab") db.tab.insert({"id":1}) |
创建数据库（创建collection） 创建数据库（插入数据也会被创建） |
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db.copyDatabase("mydb", "newmydb", "127.0.0.1") |
复制为另一个新的数据库 |
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db.dropDatabase() |
删除数据库 |
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Collection定义操作（集合必须以字母或下划线开头） |
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db.createCollection("tab",{size:1024,max:1000,capped:true}) db.tab.insert({"id":1}) |
创建collections 并做限制（如创建“tab”） (插入数据也会创建collections) |
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show collections |
查看当前数据库所有collections |
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db.tab.drop() |
删除collections |
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db.tab.update({},{$rename:{"name":"newname"}},false,true) |
更改所有行的字段名name为newname |
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db.getCollection(‘tab‘).renameCollection(‘newtab‘) db.newtab.renameCollection(‘tab‘) |
更改collection名称 |
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Collection 数据操作 |
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db.tab.save({"id":2}) db.tab.insert({"id":3}) db.tab.insert([{ size: "S", qty: 25 }, { size: "M", qty: 50 }]) db.tab.insert({ array :[{ size: "S", qty: 25 }, { size: "M", qty: 50 } ]}) |
插入数据到collections （会自动生成唯一列 “_id”） 插入多行（相当： insert into tab values(“S”,1), (“M”,50)） 字段中插入子集 |
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db.tab.update({"id":1},{$set:{"id":5}}) |
更改数据（id值由1更改为5） |
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db.tab.update({ id:2},{id:6, name:‘E‘}) |
将id=2的行更新为新的行 |
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db.tab.update({"id":1},{$unset:{ name:‘120‘}}) |
删除一个键值对（删除id=2中的字段name） |
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db.tab.update({"id":1},{$push:{ name:‘C‘}}) |
往id=1的行 字段为name数组中插入元素’C’ |
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db.tab.update({"id":1},{$pull:{ name:‘C‘}}) |
从id=1的行 字段为name数组中删除所有元素’C’ |
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db.tab.remove({"id":3}) db.tab.remove({"id":3},1) db.tab.remove({}) |
删除id=3的所有记录 删除id=3的第一条记录 删除所有记录 |
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Collection查询数据操作 |
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Select * from tab |
db.tab.find() db.tab.find({}) |
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Select id from tab |
db.tab.find({},{"id":1}) #({条件},{字段:0/1}) db.tab.find({},{"_id":0,"id":1}) db.tab.aggregate({ $project : {id : 1 }}); db.tab.find({id:{$exists:1}}); |
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Select * from tab where id=1 |
db.tab.find( { id :1}) |
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Select id from tab where id=1 |
db.tab.find({id :1},{"_id":0,"id":1}) |
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Select * from tab where id<>1 |
db.tab.find({id:{$ne:1}}) |
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Select * from tab where id>2 |
db.tab.find( { id: { $gt: 2} } ) |
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Select * from tab where id<3 |
db.tab.find( { id: { $lt: 3} } ) |
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Select * from tab where id>=2 |
db.tab.find( { id: { $gte: 2 } } ) |
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Select * from tab where id<=3 |
db.tab.find( { id: { $lte: 3} } ) |
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Select * from tab where id = 1 or id = 2 |
db.tab.find({$or:[{id:3},{id:2}]}) |
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Select * from tab where id < 2 or id >4 |
db.tab.find({$or:[{id:{$gt:4}},{id:{$lt:2}}]}) |
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Select * from tab where id in (1,2) |
db.tab.find( { id: { $in: [ 1, 2 ] } } ) |
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Select * from tab where id not in (2,3) |
db.tab.find({id:{"$nin":[2,3]}}) |
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Select * from tab where id between 2 and 3 Select * from tab where id >= 2 and id <= 3 |
db.tab.find({$and:[{id:{$gte:2}},{id:{$lte:5}}]}) |
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Select * from tab where id = 1 and name = ‘kk’ |
db.tab.find({id:2, name:‘kk‘}) |
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Select distinct id from tab |
db.tab.distinct("id"); db.runCommand ( { distinct: "tab", key: "id" } ) |
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Select distinct id from tab where name = ‘A’ |
db.runCommand({distinct:‘tab‘,key:‘id‘,query:{name:‘A‘}}) |
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Select * from tab where name like ‘%A%’ |
db.tab.find({ name:{$regex:"A"}}) db.tab.find({ name:/A/}) |
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Select * from tab order by id asc |
db.tab.find().sort({id:1}) |
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Select * from tab order by id desc |
db.tab.find().sort({id:-1}) |
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Select top 5 * from tab |
db.tab.find().limit(5) |
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跳过前m条记 |
db.tab.find().skip(2) db.tab.aggregate({ $skip : 2 }); |
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跳过前m条记录，从m+1开始取n条 |
db.tab.find().skip(2).limit(3) |
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除了指定的列，其他列都显示 |
db.tab.find({id:null}) db.tab.find({},{"_id":0}) |
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查找字段id为string类型的行(参考下表格) |
db.tab.find({ id: {$type: 2}}); |
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select name,sum(id) as sumid from tab where id >0 group by name |
db.tab.group({ key:{ "name":true} # group by name ,cond:{id:{ $gt:0}} # where id >0 ,reduce:function(obj,prev) #聚合函数 { prev.sumid += obj.id; } #函数逻辑，累加id , initial: {sumid: 0 }}) #初始化 |
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Select sum(*) from tab |
db.tab.group({key:{},cond:{} ,reduce:function(obj,prev) { prev.sumid += obj.id; },initial: {sumid: 0 }}); |
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Select sum(*) as newcol from tab |
db.tab.aggregate([{$group:{_id:"$by_user",newcol:{$sum:"$id"}}}]) |
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Select count(*) from tab |
db.tab.count() 或者 db.tab.find().count() |
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Select count(*) from tab |
db.tab.group({key:{},cond:{}, reduce:function(obj,prev) { prev.sumid += 1; },initial: {sumid: 0 }}); |
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Select avg(*) from tab |
db.tab.aggregate([{$group:{_id:"$by_user",newcol:{$avg:"$id"}}}]) |
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Select max(*) from tab |
db.tab.find().sort({id:-1}).limit(1) db.tab.aggregate([{$group:{_id:"$by_user",newcol:{$max:"$id"}}}]) |
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Select min(*) from tab |
db.tab.find().sort({id:1}).limit(1) db.tab.aggregate([{$group:{_id:"$by_user",newcol:{$min:"$id"}}}]) |
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#元素查询 #db.tab.insert({ratings: [ 5, 8, 9 ] }) db.tab.find({ ratings: [ 5, 8, 9 ] } ) #查找匹配的数组 db.tab.find({ ratings: 5 }) #查找元素中含“5”的记录 db.tab.find({ ratings:{$elemMatch:{$gt:8,$lt:10}}}) #元素匹配查找 #内嵌文档 #db.tab.insert({producer:{company: ‘ABC‘,address: ‘Street‘}}) #db.tab.insert({producer:[{ company: ‘ABC‘,address: ‘Street‘},{ company: ‘KK‘,address: ‘Street2‘}] }) db.tab.find({producer:{company: ‘ABC‘,address: ‘Street‘}}) db.tab.find({‘producer.company‘: ‘ABC‘}) db.tab.find( { ‘producer.0.address‘: ‘Street‘} ) #字段‘producer的第一个元素的address=’ Street’ |
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类型描述 |
类型值 |
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Double |
1 |
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String |
2 |
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Object |
3 |
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Array |
4 |
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Binary data |
5 |
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Object id |
7 |
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Boolean |
8 |
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Date |
9 |
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Null |
10 |
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Regular expression |
11 |
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JavaScript code |
13 |
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Symbol |
14 |
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JavaScript code with scope |
15 |
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32-bit integer |
16 |
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Timestamp |
17 |
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64-bit integer |
18 |
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Min key |
255 |
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Max key |
127 |