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這期內(nèi)容當(dāng)中小編將會(huì)給大家?guī)?lái)有關(guān)MongoDB數(shù)據(jù)庫(kù)中有哪些常用的命令,文章內(nèi)容豐富且以專業(yè)的角度為大家分析和敘述,閱讀完這篇文章希望大家可以有所收獲。
help db.help(); db.yourColl.help();
use raykaeso;
當(dāng)創(chuàng)建一個(gè)集合(table)的時(shí)候會(huì)自動(dòng)創(chuàng)建當(dāng)前數(shù)據(jù)庫(kù)
show dbs;
db.dropDatabase();
db.cloneDatabase(“127.0.0.1”);
將指定機(jī)器上的數(shù)據(jù)庫(kù)的數(shù)據(jù)克隆到當(dāng)前數(shù)據(jù)庫(kù)
db.copyDatabase(“mydb”, “temp”, “127.0.0.1”);
將本機(jī)的mydb的數(shù)據(jù)復(fù)制到temp數(shù)據(jù)庫(kù)中
db.repairDatabase();
db.getName()/db;
db.stats();
db.version();
db.getMongo();
db.getPrevError(); db.resetError();
db.createCollection(“collName”, {size: 20, capped: 5, max: 100});//創(chuàng)建成功會(huì)顯示{“ok”:1} //判斷集合是否為定容量db.collName.isCapped();
db.getCollection(“account”);
db.getCollectionNames();
db.printCollectionStats();
db.yourColl.count();
db.yourColl.dataSize();
db.yourColl.getDB();
db.coll.stats();
db.coll.totalSize();
db.coll.storageSize();
db.coll.renameCollection(“ray”);
將coll重命名為ray
db.coll.drop();
db.createUser({user: 'username', pwd: 'xxxx', roles: [{role: 'readWrite', db: 'dbname'}]});
添加用戶、設(shè)置密碼、是否只讀
db.auth(“ray”, “123456”);
show users;
db.removeUser(“userName”);
db.userInfo.find();
相當(dāng)于:select* from userInfo;
默認(rèn)每頁(yè)顯示20條記錄,當(dāng)顯示不下的情況下,可以用it迭代命令查詢下一頁(yè)數(shù)據(jù)。注意:鍵入it命令不能帶“;”
但是你可以設(shè)置每頁(yè)顯示數(shù)據(jù)的大小,用DBQuery.shellBatchSize= 50;這樣每頁(yè)就顯示50條記錄了。
db.userInfo.distinct(“name”);
會(huì)過(guò)濾掉name中的相同數(shù)據(jù)
相當(dāng)于:select distict name from userInfo;
db.userInfo.find({“age”: 22});
相當(dāng)于: select * from userInfo where age = 22;
MongoDB中條件操作符有:
(>) 大于 – $gt
(<) 小于 – $lt (>=) 大于等于 – $gte
(<= ) 小于等于 – $lte
db.userInfo.find({age: {$gt: 22}}); 相當(dāng)于:select * from userInfo where age>22; db.userInfo.find({age: {$lt: 22}}); 相當(dāng)于:select * from userInfo where age<22; db.userInfo.find({age: {$gte: 25}}); 相當(dāng)于:select * from userInfo where age >= 25;
db.userInfo.find({name: /mongo/}); //相當(dāng)于%% select * from userInfo where name like ‘%mongo%';
db.userInfo.find({}, {name: 1, age: 1}); 相當(dāng)于:select name, age from userInfo;
當(dāng)然name也可以用true或false
db.userInfo.find({age: {$gt: 25}}, {name: 1, age: 1}); 相當(dāng)于:select name, age from userInfo where age <25;
升序:db.userInfo.find().sort({age: 1});
降序:db.userInfo.find().sort({age: -1});
db.userInfo.find().limit(5); 相當(dāng)于:select * from userInfo limit 5;
db.userInfo.find().skip(10); 相當(dāng)于:select count() from userInfo as total; select from userInfo limit 10,total;
db.userInfo.find().limit(10).skip(5);
可用于分頁(yè),limit是pageSize,skip是第幾頁(yè)pageSize
相當(dāng)于:select from userInfo limit 5,10;
db.userInfo.find({$or: [{age: 22}, {age: 25}]}); 相當(dāng)于:select * from userInfo where age = 22 or age = 25;
db.userInfo.findOne(); db.userInfo.find().limit(1); 相當(dāng)于:select * from userInfo limit 1;
db.userInfo.find({age: {$gte: 25}}).count(); 相當(dāng)于:select count(*) from userInfo where age >= 20;
db.userInfo.ensureIndex({name: 1}); db.userInfo.ensureIndex({name: 1, ts: -1});
db.userInfo.getIndexes();
db.userInfo.totalIndexSize();
db.users.reIndex();
db.users.dropIndex(“name_1″);
db.users.dropIndexes();
db.users.save({name: ‘zhangsan', age: 25, sex: true});
添加的數(shù)據(jù)的數(shù)據(jù)列,沒(méi)有固定,根據(jù)添加的數(shù)據(jù)為準(zhǔn)
db.users.update({age: 25}, {$set: {name: ‘changeName'}}, false, true); 相當(dāng)于:update users set name = ‘changeName' where age = 25; db.users.update({name: ‘Lisi'}, {$inc: {age: 50}}, false, true); 相當(dāng)于:update users set age = age + 50 where name = ‘Lisi'; db.users.update({name: ‘Lisi'}, {$inc: {age: 50}, $set: {name: ‘hoho'}}, false, true); 相當(dāng)于:update users set age = age + 50, name = ‘hoho' where name = ‘Lisi';
db.users.remove({age: 132});
db.users.findAndModify({ query: {age: {$gte: 25}}, sort: {age: -1}, update: {$set: {name: ‘a(chǎn)2′}, $inc: {age: 2}}, remove: true });
上述就是小編為大家分享的MongoDB數(shù)據(jù)庫(kù)中有哪些常用的命令了,如果剛好有類似的疑惑,不妨參照上述分析進(jìn)行理解。如果想知道更多相關(guān)知識(shí),歡迎關(guān)注億速云行業(yè)資訊頻道。
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