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. command to start the mongodb process.






2. Returns help information for a command.






3. changes the database on which you are working.






4. command to start the mongo shell.






5. Update call that inserts a new document if no update match is found. Allows the same code to be used for inserts as well as updates.






6. Returns all the documents matching the optional properties.






7. The standard number representation in the javascript shell.






8. Returns help information for a command.






9. Meta query conditional used to negate the selector.






10. Command to list commands and descriptions of those commands in the context of the database.






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






12. Returns the size of a document after it is converted to BSON from the JSON-like original.






13. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.






14. Standard javascript regular expressions. These can be stored in documents






15. 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"}});






16. Copies an entire database from one name on one server to another name on another server. Omit frmHostName to copy from one name to another on the same server.






17. Lists all the collections in the database in use.






18. Adds a document to a collection.






19. Contains query conditional used to check if a value contains the field value.






20. Data structure used to store all other data in mongo databases.






21. 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 },






22. Unique 12-byte ID for documents.






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






24. 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.






25. Greater than query conditional. ex: db.<col>.find({numVal: {$gt:3}});






26. Appends each value in the value_array to the field - if field is an existing array. Otherwise - it sets the field to the array value_array - if field is not present ex: { $pushAll : { field : value_array } }






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






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






29. Set or list of values.






30. Deletes documents from the collection based on the selector.






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






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






33. Javascript code. Documents can contain code as values.






34. 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 } }






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






36. Binary-encoded serialization of mongo documents.






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






38. 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 } }






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






40. Array specific conditional used to select based on the length or set-size of an array field value.






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






42. command to start the mongodb process.






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






44. String of arbitrary bytes.






45. 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.






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






47. 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.






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






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






50. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.