MongoDB
is a document-oriented, scalable, high-performance open source database. Typical application scenarios include web page data, caching, and alternative document storage.
Memorizing and using commands is a basic skill. Here is a quick checklist, which can be used as a desk manual.
| library operations | |
| switch or use a database | use mymongodb |
|---|---|
| see all libraries | show dbs |
| delete the currently used database | db.dropDatabase() |
| Clone all libraries to the current link | db.cloneDatabase(“192.160.1.1”) |
| Copy the specified library | db.cloneDatabase(“sourcedb”,”targetdb”,”192.168.1.1”) |
| View current database | db.getName() |
| Current database state | db.stats() |
| Current database version | db.version() |
| View current database connections | db.getMongo() |
| User action | |
| Add user | db.addUser(“user_name”, “password”, true) |
| User Authentication | db.auth(“username”, “password”) |
| show all users | show users; |
| delete users | db.removeUser(“username”); |
| Collection basic information | |
| Query the number of data in the collection | db.myCollection.count(); |
| View data space size | db.myCollection.dataSize(); |
| View the database where the collection is located | db.myCollection.getDB(); |
| The current state of the aggregation | db.myCollection.stats(); |
| The total size of the current collection | db.myCollection.totalSize(); |
| Collection storage size | db.myCollection.storageSize(); |
| Shard version information | db.myCollection.getShardVersion(); |
| Collection rename | db.myCollection.renameCollection(“targetCollection”); |
| delete collection | db.myCollection.drop(); |
| Addition, deletion and modification of collection data | |
| add record | db.myCollection.save({mykey:”t_key”,myvalue:”t-value”}); |
| 删除记录 | db.myCollection.remove({mykey:”t_key”}); |
| 修改记录 | db.myCollection.update({condition: xx}, {$set: {field: ‘changefield’}}, false, true); |
| 查询并修改记录 | db.myCollection.findAndModify(query: {condition1: {gte: XX}}, sort: {condition2: -1}, update: {gte: XX}}, sort: {condition2: -1}, update: {set: {target1: 'yy'}, $inc: {target2: 2}}, remove: true}); |
| 集合数据查询 | |
| 查询所有记录 | db.myCollection.find(); |
| 查询第一条记录 | db.myCollection.findOne(); |
| 数据去重 | db.myCollection.distinct(“fieldname”); |
| 数值区间查询 | db.myCollection.find({numfield:{$gte:nn}}); |
| 字符串查询 | db.myCollection.find({targetfield:/ABC/}); |
| 指定字段查询 | db.myCollection.find({},{field1:’abc’,field2:nnn}); |
| 指定返回条数查询 | db.myCollection.find().limit(m).skip(n); |
| 排序 | db.myCollection.find().sort({targetfield:-1}); //降序 |
| 统计记录数 | db.myCollection.find({target: n }).count(); |
| 索引操作 | |
| 创建 | db.myCollection.ensureIndex({targetfield: 1}); |
| 查询所有索引 | db.myCollection.getIndexes(); |
| 查询所有索引大小 | db.myCollection.totalIndexSize(); |
| 查询索引信息 | db.myCollection.reIndex({targetfield: 1}); |
| 删除指定索引 | db.myCollection.dropIndex(“targetfield”); |
| 删除所有索引 | db.myCollection.dropIndexes(); |
| 辅助命令 | |
| 查询错误信息 | db.getPrevError(); |
| 清空错误信息 | db.resetError(); |
| 各种帮助信息 | help; db.help(); db.myCollection.help(); db.myCollection.find().help(); rs.help(); |