MongoDB 命令初步

1. 检查当前instance

> dbtest

2. 列出所有instance

> show dbslocal0.078125GBmonk-app0.203125GBmonk-demo(empty)

3. 保存

> j = { name : "mongo" };  { "name" : "mongo" }> t = { x : 3 };  { "x" : 3 }> db.things.save(j);  > db.things.save(t); > db.things.find();{ "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }{ "_id" : ObjectId("551bf15f2a1d94d79c992e17"), "x" : 3 }

4. for 循环

> for (var i = 1; i <= 20; i++) db.things.save({x : 4, j : i}); > db.things.find();{ "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }{ "_id" : ObjectId("551bf15f2a1d94d79c992e17"), "x" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e18"), "x" : 4, "j" : 1 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e19"), "x" : 4, "j" : 2 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1a"), "x" : 4, "j" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1b"), "x" : 4, "j" : 4 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1c"), "x" : 4, "j" : 5 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1d"), "x" : 4, "j" : 6 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1e"), "x" : 4, "j" : 7 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1f"), "x" : 4, "j" : 8 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e20"), "x" : 4, "j" : 9 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e21"), "x" : 4, "j" : 10 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e22"), "x" : 4, "j" : 11 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e23"), "x" : 4, "j" : 12 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e24"), "x" : 4, "j" : 13 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e25"), "x" : 4, "j" : 14 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e26"), "x" : 4, "j" : 15 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e27"), "x" : 4, "j" : 16 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e28"), "x" : 4, "j" : 17 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e29"), "x" : 4, "j" : 18 }Type "it" for more

5. cursor

> var cursor = db.things.find(); > while (cursor.hasNext()) printjson(cursor.next());{ "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }{ "_id" : ObjectId("551bf15f2a1d94d79c992e17"), "x" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e18"), "x" : 4, "j" : 1 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e19"), "x" : 4, "j" : 2 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1a"), "x" : 4, "j" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1b"), "x" : 4, "j" : 4 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1c"), "x" : 4, "j" : 5 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1d"), "x" : 4, "j" : 6 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1e"), "x" : 4, "j" : 7 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1f"), "x" : 4, "j" : 8 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e20"), "x" : 4, "j" : 9 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e21"), "x" : 4, "j" : 10 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e22"), "x" : 4, "j" : 11 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e23"), "x" : 4, "j" : 12 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e24"), "x" : 4, "j" : 13 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e25"), "x" : 4, "j" : 14 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e26"), "x" : 4, "j" : 15 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e27"), "x" : 4, "j" : 16 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e28"), "x" : 4, "j" : 17 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e29"), "x" : 4, "j" : 18 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e2a"), "x" : 4, "j" : 19 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e2b"), "x" : 4, "j" : 20 }

6. forEach

> db.things.find().forEach(printjson);
{ "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }
{ "_id" : ObjectId("551bf15f2a1d94d79c992e17"), "x" : 3 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e18"), "x" : 4, "j" : 1 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e19"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e1a"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e1b"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e1c"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e1d"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e1e"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e1f"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e20"), "x" : 4, "j" : 9 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e21"), "x" : 4, "j" : 10 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e22"), "x" : 4, "j" : 11 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e23"), "x" : 4, "j" : 12 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e24"), "x" : 4, "j" : 13 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e25"), "x" : 4, "j" : 14 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e26"), "x" : 4, "j" : 15 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e27"), "x" : 4, "j" : 16 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e28"), "x" : 4, "j" : 17 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e29"), "x" : 4, "j" : 18 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e2a"), "x" : 4, "j" : 19 }
{ "_id" : ObjectId("551bf1b02a1d94d79c992e2b"), "x" : 4, "j" : 20 }

7. Index

> var cursor = db.things.find(); > printjson(cursor[4]); { "_id" : ObjectId("551bf1b02a1d94d79c992e1a"), "x" : 4, "j" : 3 }

8. Array

> var arr = db.things.find().toArray();  > arr[5]; { "_id" : ObjectId("551bf1b02a1d94d79c992e1b"), "x" : 4, "j" : 4 }

9. Find

> db.things.find({name:"mongo"}).forEach(function(x) {print(tojson(x));});  { "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }

10. Find & forEach

> db.things.find({x:4}).forEach(function(x) {print(tojson(x));});{ "_id" : ObjectId("551bf1b02a1d94d79c992e18"), "x" : 4, "j" : 1 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e19"), "x" : 4, "j" : 2 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1a"), "x" : 4, "j" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1b"), "x" : 4, "j" : 4 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1c"), "x" : 4, "j" : 5 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1d"), "x" : 4, "j" : 6 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1e"), "x" : 4, "j" : 7 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1f"), "x" : 4, "j" : 8 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e20"), "x" : 4, "j" : 9 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e21"), "x" : 4, "j" : 10 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e22"), "x" : 4, "j" : 11 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e23"), "x" : 4, "j" : 12 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e24"), "x" : 4, "j" : 13 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e25"), "x" : 4, "j" : 14 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e26"), "x" : 4, "j" : 15 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e27"), "x" : 4, "j" : 16 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e28"), "x" : 4, "j" : 17 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e29"), "x" : 4, "j" : 18 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e2a"), "x" : 4, "j" : 19 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e2b"), "x" : 4, "j" : 20 }

11. 过滤结果

> db.things.find({x:4}, {j:true}).forEach(printjson); { "_id" : ObjectId("551bf1b02a1d94d79c992e18"), "j" : 1 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e19"), "j" : 2 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1a"), "j" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1b"), "j" : 4 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1c"), "j" : 5 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1d"), "j" : 6 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1e"), "j" : 7 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e1f"), "j" : 8 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e20"), "j" : 9 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e21"), "j" : 10 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e22"), "j" : 11 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e23"), "j" : 12 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e24"), "j" : 13 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e25"), "j" : 14 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e26"), "j" : 15 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e27"), "j" : 16 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e28"), "j" : 17 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e29"), "j" : 18 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e2a"), "j" : 19 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e2b"), "j" : 20 }

12. Projection取一条结果

> printjson(db.things.findOne({name:"mongo"}));{ "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }> db.things.find({name:"mongo"}).limit(1);{ "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }

13. Projection取三条结果

> db.things.find().limit(3); { "_id" : ObjectId("551bf1552a1d94d79c992e16"), "name" : "mongo" }{ "_id" : ObjectId("551bf15f2a1d94d79c992e17"), "x" : 3 }{ "_id" : ObjectId("551bf1b02a1d94d79c992e18"), "x" : 4, "j" : 1 }

14. 查看函数定义

> printjsonfunction (x){    print( tojson( x ) );}