Test your basic knowledge |

Subject : it-skills
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Contains query conditional used to check if a value contains the field value.






2. Used to represent both a null value and a nonexistent field.






3. Adds a document to a collection.






4. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.






5. Not supported by the javascript shell and are converted to 64-bit floating point numbers.






6. Not supported by the javascript shell and are converted to 64-bit floating point numbers.






7. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }






8. The standard number representation in the javascript shell.






9. Set or list of values.






10. Command to get help docs on a specific command at the collection level.






11. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});






12. In BSON - represents the largest possible value.






13. ...






14. command to start the mongodb process.






15. Stored as milliseconds since the epoch.






16. Positional operator that holds the position of the first matched array item in the query. Used to find an array member and then manipulate it. ex: {$inc:{'comments.$.votes':1}} where comments looks like: "comments" : [ { "by" : "joe", "votes" : 3 },






17. set of UTF-8 characters.






18. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});






19. Adds a document to a collection.






20. command to start the mongodb process.






21. Array specific conditional allowing matching on multiple elements within an array. The operation is non strict on the sequence of the values in the passed selector array.






22. command to start the mongo shell.






23. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});






24. Returns all the documents matching the optional properties.






25. Update modifier that set the value of a key and if the key does not exist, it will create the key. ex: db.<col>.update({selector},{"$set":{"someKey":"someValue"}});






26. Query conditional allowing the selector to choose between more than one optional criteria.






27. Special keys passed in an update call to specify complex update operations - such as alter - adding - or removing keys - and even manipulating arrays and embedded documents.






28. Does not contain query conditional used to select documents with the field that is not in the selector list of values.






29. Updates all matching documents, not just the first, that match the selector.






30. A document contained by a parent document. The embedded document is a value of a key in the parent document.






31. Operator allowing the partial specification of fields in an embedded document in an array.






32. Removes an element from an array based on the value of the field option being 1 or -1 for last or first element respectively. ex: { $pop : { field : -1 } }






33. Deletes a given field. ex: { $unset : { field : 1} }






34. Appends a value to field - if the field is an existing array. Otherwise it sets the field to the array [value] if field is not present. ex: { $push : { field : value } }






35. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.






36. Returns one document matching the optional properties.






37. Flushes all pending writes to data files. The lock option allows one to safely snapshot the database's data files. The async option returns focus to the console immediately while the task runs in the background.






38. Operator allowing the execution of arbitrary javascript as part of the selector.






39. Adds a value to the array only if its not in the array already. Otherwise, if the field is not present, it sets the field to the array value. ex: { $addToSet : { a : { $each : [ 3 , 5 , 6 ] } } }






40. Used to describe a variable as not having been initialized.






41. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}






42. Greater than or equal query conditional. ex: db.<col>.find({numVal: {$gte:3}});






43. Standard binary data type.






44. command to start the mongo shell.






45. changes the database on which you are working.






46. Meta query conditional used to negate the selector.






47. Renames a field from the one indicated to the new field name. ex: { $rename : { old_field_name : new_field_name } }






48. Clone the current database (implied by 'db') from another host.






49. changes the database on which you are working.






50. Command to get help docs on a specific command at the db level.