Difference between revisions of "MongoDB Delete"

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Department 40 has closed down:
 
Department 40 has closed down:
  
  db.deptCollection.deleteOne({deptno:40})
+
  db.dept.deleteOne({deptno:40})
  
 
Note, if the query_criteria only returns one document, '''remove()''' and '''deleteOne()''' will have the same effect.
 
Note, if the query_criteria only returns one document, '''remove()''' and '''deleteOne()''' will have the same effect.
Line 37: Line 37:
 
Check that the collection has gone:
 
Check that the collection has gone:
  
  db.deptCollection.find({deptno:40})
+
  db.dept.find({deptno:40})
  
 
== Next Step ==
 
== Next Step ==
  
 
This concludes the section on manipulating collections. Return to the [[MongoDB_Workbook|Workbook]].
 
This concludes the section on manipulating collections. Return to the [[MongoDB_Workbook|Workbook]].

Revision as of 17:01, 12 November 2017

Main Page >> MongoDB >>MongoDB Workbook >> Deleting a Document/Collection

Deleting a Document

At some stage you may want to delete a document from a collection. The format is:

db.collectionName.deleteOne(query_criteria) /* deletes the first document found that matches the query criteria */
db.collectionName.remove(query_criteria) /* deletes all documents found that matches the query criteria */
db.collectionName.remove(query_criteria) /* deletes all documents in a collection (use with care!) */

Deleting a Collection

If you want to drop a collection completely, including any data held in it:

db.collectionName.drop() /* removes a collection completely (use with care!) */


Delete Department 40

Department 40 has closed down:

db.dept.deleteOne({deptno:40})

Note, if the query_criteria only returns one document, remove() and deleteOne() will have the same effect.


Check that the collection has gone:

db.dept.find({deptno:40})

Next Step

This concludes the section on manipulating collections. Return to the Workbook.