count

The count command counts the number of documents in a collection. The command returns a document that contains the count as well as the command status. The count command takes the following prototype form:

{ count: <collection>, query: <query>, limit: <limit>, skip: <skip> }

The command fields are as follows:

Consider the following examples of the count command:

• Count the number of all documents in the orders collection:

  db.runCommand( { count: 'orders' } )
  

  In the result, the n, which represents the count, is 26 and the command status ok is 1:

  { "n" : 26, "ok" : 1 }
  

• Count the number of the documents in the orders collection with the field ord_dt greater than new Date('01/01/2012'):

  db.runCommand( { count:'orders',
                   query: { ord_dt: { $gt: new Date('01/01/2012') } }
                 } )
  

  In the result, the n, which represents the count, is 13 and the command status ok is 1:

  { "n" : 13, "ok" : 1 }
  

• Count the number of the documents in the orders collection with the field ord_dt greater than new Date('01/01/2012') skipping the first 10 matching records:

  db.runCommand( { count:'orders',
                   query: { ord_dt: { $gt: new Date('01/01/2012') } },
                   skip: 10 }  )
  

  In the result, the n, which represents the count, is 3 and the command status ok is 1:

  { "n" : 3, "ok" : 1 }