MongoDB Basic Operations

In MongoDB, a database might contain multiple collections, just as a database in MySQL might contain multiple tables, and a collection might contain multiple documents, just as a table in MySQL contains more than one piece of data.

Basic Operations Command:show dbs   View all database lists use <dbname>  connection to the specified database db   view the currently used database >  use testdb                       #  Create a TestDB database switched to db testdb>  show dbsadmin       0.078gbceilometer  1.953gblocal &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;6.075GB listed in the database does not have TestDB or display TestDB (empty), because there is nothing in TestDB. > use testdb                      #  Delete TestDB Database switched to db testdb>  Db.dropdatabase () {  "Dropped"  :  "TestDB",  "OK"  : 1 }> use  testdb                              #  Create Collection switched to db testdb> db.createcollection (' users ') {   "OK"  : 1 }> show collectionssystem.indexesusers> show  collections            #  Delete Collection System.indexesusers> db.users.drop () true> show collectionssystem.indexes>  Db.createcollection (' users ')    #  insert data into the collection if the collection is not automatically created {  "OK"  : 1 }>  show collectionssystem.indexesusers> db.users.insert ([... { name :  ' Yao ',...  email :  ' [email protected] ' ... &nbsp,},...  { name:  ' shen ',...   email :  ' [email protected] ' ...  }... ]) Bulkwriteresult ({"Writeerrors"  : [  ], "writeconcernerrors" &NBSP;:&NBSP;[&NBSP;], "ninserted"  : 2, "nupserted"  : 0, " Nmatched " : 0," nmodified " : 0," NremoVed " : 0," upserted "&NBSP;:&NBSP;[&NBSP;]}) > db.users.save ([                           #  save can also implement the above Insert function ... { name :  ' test ',...  email :   ' [email protected] ' ...  }... ]) Bulkwriteresult ({"writeerrors" &NBSP;:&NBSP;[&NBSP;], " Writeconcernerrors "&NBSP;:&NBSP;[&NBSP;]," ninserted " : 1," nupserted " : 0," nMatched "&NBSP;:  0, "nmodified"  : 0, "nremoved"  : 0, "upserted" &NBSP;:&NBSP;[&NBSP;]}) data query command:>  Db.users.find ()                #  find returns all data records without any parameters {  "_id"  : objectid ("55e1cf2326f975bfd9b902e9"),  "name" &NBSP;:   "Yao",  "email"  :  "[email protected]"  }{  "_id"  : objectid (" 55e1cf2326f975bfd9b902ea "), " name "&NBsp;:  "shen",  "email"  :  "[email protected]"  }{  "_id"  : objectid (" 55e1d32b26f975bfd9b902ec "), " name " : " test ", " email " : " [email protected] "  }> db.users.find (). Pretty ()      # pretty query output more beautiful display {"_id" &NBSP;:  objectid ("55e1cf2326f975bfd9b902e9"), "name"  :  "Yao", "email"  :  "[email protected ] "} {" _id " : objectid (" 55e1cf2326f975bfd9b902ea ")," name " : " shen "," email " : " [ Email protected] "} {" _id " : objectid (" 55e1d32b26f975bfd9b902ec ")," name " : " Test "," Email " : " [email protected] "}> db.users.find ({' name ': ' Yao ', ' email ': ' [email  Protected]). Pretty ()   # find pass in multiple key-value pairs, MongoDB for multiple key-value pairs as and processing {"_id"  : objectid (" 55e1cf2326f975bfd9b902e9 ")," name " : " Yao "," email " : " [email protected] "}>  Db.users.find ({$or:  [{' name ': ' YAo '}, {' email ': ' [email protected] '} '}). Pretty ()   # or query statement requires $or keyword {"_id"  :  ObjectId ("55e1cf2326f975bfd9b902e9"), "name"  :  "Yao", "email"  :  "[email protected]"} {"_ ID " : objectid" ("55e1d32b26f975bfd9b902ec"), "name"  :  "test", "email"  :  "[email  protected] "}> db.users.find ({' name ':  ' Yao ',  $or:  [{' name ': ' Yao '}, {' email ': ' [ Email protected]}). Pretty ()  # and, or together with {"_id"  : objectid ("55e1cf2326f975bfd9b902e9 ")," name " : " Yao "," email " : " [email protected] "}

This article is from the "The-way-to-cloud" blog, make sure to keep this source http://iceyao.blog.51cto.com/9426658/1689662

MongoDB Basic Operations