Test your basic knowledge |

Mongo Db

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. Standard javascript regular expressions. These can be stored in documents
db.<col>.update({selector},{document});
help
$unset
regular expression

2. command to start the mongo shell.
$where
mongo
$all
64-Bit Integer

3. 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 } }
$pushAll
show collections
$size
document

4. Renames a field from the one indicated to the new field name. ex: { $rename : { old_field_name : new_field_name } }
$rename
object id
32-Bit Integer
date

5. Data structure used to store all other data in mongo databases.
64-Bit Integer
binary data
db.cloneDatabase(fromhost)
document

6. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
$not
$pull
db.<collection>.insert({document});
batch insert

7. 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.
$pullAll
db.<collection>.findOne([properties]);
$mod
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);

8. Returns all the documents matching the optional properties.
code
db.<collection>.insert({document});
db.getLastError()
db.<collection>.find([properties]);

9. Updates all matching documents, not just the first, that match the selector.
db.cloneDatabase(fromhost)
db.<collection>.findOne([properties]);
$size
Multi-updates

10. command to start the mongodb process.
64-bit floating point numbers
mongod
$mod
$size

11. Returns help information for a command.
32-Bit Integer
db.commandHelp("commandName")
$size
$inc

12. Operator allowing the execution of arbitrary javascript as part of the selector.
$where
string
db.commandHelp("commandName")
$addToSet

13. Query conditional allowing the selector to choose between more than one optional criteria.
$or
$inc
use <database name>
regular expression

14. Update a document in the collection.
date
db.<collection>.find([properties]);
db.<col>.update({selector},{document});
maximum value

15. Set or list of values.
array
Object.bsonsize({document});
string
minimum value

16. Deletes documents from the collection based on the selector.
binary data
null
help
db.<col>.remove({selector});

17. 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 } }
null
$push
$lt
mongo

18. Returns the size of a document after it is converted to BSON from the JSON-like original.
db.commandHelp("commandName")
$pushAll
regular expression
Object.bsonsize({document});

19. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
db.<collection>.find([properties]);
32-Bit Integer
$lt
use <database name>

20. Clone the current database (implied by 'db') from another host.
null
$gte
db.cloneDatabase(fromhost)
code

21. changes the database on which you are working.
Object.bsonsize({document});
64-Bit Integer
use <database name>
document

22. Stored as milliseconds since the epoch.
date
$pop
show collections
db.runCommand({fsync:1,lock:1,async:1})

23. ...
use <database name>
$all
batch insert
$in

24. 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.
$gt
Cursor
$nin
$all

25. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});
$ne
db.cloneDatabase(fromhost)
document
$gte

26. Meta query conditional generating a modulus with the selector operand. Checks to see if the field value when divided by one value has the remainder of the second value.
$pushAll
$mod
$in
db.cloneDatabase(fromhost)

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.
code
Object.bsonsize({document});
maximum value
Update Modifiers

28. Returns all the documents matching the optional properties.
minimum value
db.<collection>.insert({document});
$pull
db.<collection>.find([properties]);

29. 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 ] } } }
$addToSet
binary data
db.<collection>.find([properties]);
db.myCollection.ensureIndex({keypattern},[{options}])

30. In BSON - represents the largest possible value.
$not
array
mongo
maximum value

31. A document contained by a parent document. The embedded document is a value of a key in the parent document.
$mod
BSON
db.commandHelp("commandName")
embedded document

32. The standard number representation in the javascript shell.
64-bit floating point numbers
$unset
db.<collection>.find([properties]);
32-Bit Integer

33. 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 },
Multi-updates
db.myCollection.ensureIndex({keypattern},[{options}])
64-Bit Integer
$

34. Array specific conditional used to select based on the length or set-size of an array field value.
db.<collection>.find([properties]);
$size
boolean
date

35. changes the database on which you are working.
mongod
$pop
use <database name>
date

36. Unique 12-byte ID for documents.
boolean
use <database name>
object id
$ne

37. Returns help information for a command.
use <database name>
db.commandHelp("commandName")
db.<col>.help([commandName]);
db.<collection>.insert({document});

38. Syntax used for selectors to be specific to a certain element position within an array.
array
$ne
db.<col>.help([commandName]);
key.index

39. Used to describe a variable as not having been initialized.
db.<collection>.findOne([properties]);
undefined
db.cloneDatabase(fromhost)
Object.bsonsize({document});

40. Command to get help docs on a specific command at the db level.
db.help([commandName]);
32-Bit Integer
$all
Cursor

41. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
mongod
embedded document
mongod
Cursor

42. Returns one document matching the optional properties.
$all
db.<collection>.findOne([properties]);
$size
object id

43. Standard binary data type.
Update Modifiers
regular expression
boolean
$pop

44. Lists all the collections in the database in use.
db.runCommand({fsync:1,lock:1,async:1})
batch insert
show collections
Upsert

45. String of arbitrary bytes.
db.help([commandName]);
binary data
db.<collection>.find([properties]);
$pull

46. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
$unset
$slice
$or
$lte

47. Javascript code. Documents can contain code as values.
code
BSON
$lte
string

48. Operator allowing the partial specification of fields in an embedded document in an array.
use <database name>
$elemMatch
object id
use <database name>

49. Deletes documents from the collection based on the selector.
date
db.<col>.remove({selector});
db.<collection>.findOne([properties]);
db.<col>.update({selector},{document});

50. Deletes a given field. ex: { $unset : { field : 1} }
db.<col>.help([commandName]);
$unset
Multi-updates
$pushAll