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. Stored as milliseconds since the epoch.
$pop
document
boolean
date

2. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
Cursor
$ne
$set
mongod

3. Data structure used to store all other data in mongo databases.
boolean
regular expression
document
$all

4. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}
db.<collection>.find([properties]);
BSON
document
$inc

5. Updates all matching documents, not just the first, that match the selector.
$pullAll
$or
Multi-updates
null

6. Meta query conditional used to negate the selector.
$not
db.runCommand({fsync:1,lock:1,async:1})
db.getLastError()
undefined

7. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
db.<collection>.insert({document});
$or
db.commandHelp("commandName")
32-Bit Integer

8. Contains query conditional used to check if a value contains the field value.
db.<collection>.insert({document});
$inc
$elemMatch
$in

9. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
$ne
key.index
maximum value
$pullAll

10. Array specific conditional used to select based on the length or set-size of an array field value.
Multi-updates
string
64-Bit Integer
$size

11. A document contained by a parent document. The embedded document is a value of a key in the parent document.
$addToSet
mongod
binary data
embedded document

12. set of UTF-8 characters.
db.cloneDatabase(fromhost)
string
db.runCommand({fsync:1,lock:1,async:1})
$pull

13. command to start the mongodb process.
$pushAll
mongod
$where
embedded document

14. 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 } }
code
boolean
64-bit floating point numbers
$push

15. The standard number representation in the javascript shell.
db.<col>.update({selector},{document});
mongod
$not
64-bit floating point numbers

16. Javascript code. Documents can contain code as values.
code
$pullAll
db.<col>.help([commandName]);
string

17. Adds a document to a collection.
$lt
db.myCollection.ensureIndex({keypattern},[{options}])
db.<collection>.insert({document});
db.commandHelp("commandName")

18. 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.
$not
$mod
help
show collections

19. Standard javascript regular expressions. These can be stored in documents
db.getLastError()
show collections
regular expression
db.<collection>.find([properties]);

20. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
$not
$push
$lt
undefined

21. 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"}});
$in
$set
use <database name>
BSON

22. String of arbitrary bytes.
code
db.runCommand({fsync:1,lock:1,async:1})
mongod
binary data

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

24. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
$pull
$mod
$elemMatch
$nin

25. Unique 12-byte ID for documents.
db.commandHelp("commandName")
db.help([commandName]);
object id
use <database name>

26. Syntax used for selectors to be specific to a certain element position within an array.
db.help([commandName]);
BSON
key.index
mongo

27. Clone the current database (implied by 'db') from another host.
db.cloneDatabase(fromhost)
$addToSet
$gte
db.<col>.update({selector},{document});

28. Command to get help docs on a specific command at the db level.
$lte
db.help([commandName]);
db.<collection>.find([properties]);
Upsert

29. Returns one document matching the optional properties.
db.<collection>.findOne([properties]);
$mod
db.cloneDatabase(fromhost)
$pop

30. Returns help information for a command.
64-Bit Integer
$rename
db.commandHelp("commandName")
db.<collection>.findOne([properties]);

31. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
db.cloneDatabase(fromhost)
maximum value
$nin
Cursor

32. Lists all the collections in the database in use.
date
embedded document
show collections
Multi-updates

33. Returns all the documents matching the optional properties.
$set
minimum value
db.<collection>.find([properties]);
key.index

34. Adds a document to a collection.
show collections
null
db.<collection>.insert({document});
db.<collection>.find([properties]);

35. 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 },
minimum value
$elemMatch
db.<col>.update({selector},{document});
$

36. Set or list of values.
array
help
db.<collection>.find([properties]);
$pop

37. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
db.myCollection.ensureIndex({keypattern},[{options}])
$mod
db.commandHelp("commandName")

38. Query conditional allowing the selector to choose between more than one optional criteria.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
help
$lte
$or

39. 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 } }
$lte
Update Modifiers
$pop
object id

40. 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.
$push
Upsert
$elemMatch
db.help([commandName]);

41. Returns all the documents matching the optional properties.
$
$pull
64-bit floating point numbers
db.<collection>.find([properties]);

42. Returns help information for a command.
db.commandHelp("commandName")
regular expression
null
db.getLastError()

43. command to start the mongo shell.
help
db.commandHelp("commandName")
$size
mongo

44. Update a document in the collection.
db.<col>.update({selector},{document});
db.<collection>.insert({document});
$not
code

45. Returns the size of a document after it is converted to BSON from the JSON-like original.
db.<collection>.insert({document});
Object.bsonsize({document});
$addToSet
$pushAll

46. 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.
db.runCommand({fsync:1,lock:1,async:1})
$where
mongod
db.myCollection.ensureIndex({keypattern},[{options}])

47. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
db.<collection>.insert({document});
db.getLastError()
mongod
code

48. changes the database on which you are working.
$unset
$all
$addToSet
use <database name>

49. Standard binary data type.
array
$rename
boolean
$push

50. Used to represent both a null value and a nonexistent field.
$unset
Upsert
null
db.<collection>.insert({document});