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. Adds a document to a collection.
$pull
db.<collection>.insert({document});
$gt
date

2. Standard binary data type.
boolean
mongo
64-Bit Integer
db.<col>.remove({selector});

3. Lists all the collections in the database in use.
64-Bit Integer
show collections
$in
Cursor

4. set of UTF-8 characters.
batch insert
$all
$pull
string

5. Renames a field from the one indicated to the new field name. ex: { $rename : { old_field_name : new_field_name } }
code
$rename
$push
minimum value

6. 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 },
$
$where
$addToSet
batch insert

7. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
64-bit floating point numbers
$inc
$size
32-Bit Integer

8. command to start the mongo shell.
db.cloneDatabase(fromhost)
mongo
BSON
$rename

9. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
Object.bsonsize({document});
$slice
object id
$set

10. Deletes a given field. ex: { $unset : { field : 1} }
$lte
$lt
$unset
$elemMatch

11. ...
$unset
$size
db.<col>.help([commandName]);
batch insert

12. Adds a document to a collection.
regular expression
db.<collection>.insert({document});
$mod
$slice

13. Meta query conditional used to negate the selector.
$not
$elemMatch
BSON
undefined

14. In BSON - represents the smallest possible value.
regular expression
64-Bit Integer
$not
minimum value

15. Set or list of values.
minimum value
array
$mod
$pop

16. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
$not
db.cloneDatabase(fromhost)
$lt
Upsert

17. Returns help information for a command.
db.commandHelp("commandName")
db.<collection>.insert({document});
mongod
binary data

18. 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.
minimum value
db.runCommand({fsync:1,lock:1,async:1})
32-Bit Integer
64-Bit Integer

19. 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 } }
$push
object id
64-bit floating point numbers
$

20. 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.
$lte
$elemMatch
Update Modifiers
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);

21. Deletes documents from the collection based on the selector.
$lt
db.cloneDatabase(fromhost)
db.<col>.remove({selector});
db.<col>.update({selector},{document});

22. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
maximum value
$pushAll
regular expression
$pullAll

23. Binary-encoded serialization of mongo documents.
batch insert
use <database name>
BSON
$all

24. Updates all matching documents, not just the first, that match the selector.
show collections
Multi-updates
db.<collection>.findOne([properties]);
db.help([commandName]);

25. Returns all the documents matching the optional properties.
$pull
boolean
db.help([commandName]);
db.<collection>.find([properties]);

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

27. String of arbitrary bytes.
binary data
string
32-Bit Integer
$nin

28. Query conditional allowing the selector to choose between more than one optional criteria.
$
$or
undefined
$slice

29. Command to get help docs on a specific command at the collection level.
document
db.<col>.help([commandName]);
$not
Object.bsonsize({document});

30. Returns all the documents matching the optional properties.
binary data
Multi-updates
boolean
db.<collection>.find([properties]);

31. Returns the size of a document after it is converted to BSON from the JSON-like original.
minimum value
db.myCollection.ensureIndex({keypattern},[{options}])
$lt
Object.bsonsize({document});

32. Standard javascript regular expressions. These can be stored in documents
date
regular expression
$lte
$inc

33. Clone the current database (implied by 'db') from another host.
object id
db.<col>.remove({selector});
db.<collection>.find([properties]);
db.cloneDatabase(fromhost)

34. In BSON - represents the largest possible value.
help
null
maximum value
$in

35. Command to list commands and descriptions of those commands in the context of the database.
help
mongo
binary data
$

36. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
regular expression
64-Bit Integer
Multi-updates
key.index

37. Returns one document matching the optional properties.
db.<collection>.findOne([properties]);
db.commandHelp("commandName")
use <database name>
binary data

38. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
BSON
db.myCollection.ensureIndex({keypattern},[{options}])
$gte
$rename

39. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
$addToSet
boolean
db.getLastError()
Object.bsonsize({document});

40. Returns help information for a command.
db.commandHelp("commandName")
$size
use <database name>
$lt

41. Javascript code. Documents can contain code as values.
$gt
mongo
code
Multi-updates

42. Contains query conditional used to check if a value contains the field value.
32-Bit Integer
$in
db.<col>.help([commandName]);
Upsert

43. 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.
mongo
$all
mongod
$push

44. 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
db.cloneDatabase(fromhost)
$lt
$elemMatch

45. Clone the current database (implied by 'db') from another host.
binary data
64-Bit Integer
db.cloneDatabase(fromhost)
null

46. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
Update Modifiers
db.getLastError()
$nin
db.<collection>.find([properties]);

47. Unique 12-byte ID for documents.
db.<collection>.find([properties]);
object id
$unset
$lte

48. 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.
$not
Update Modifiers
$inc
$all

49. 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.
$mod
db.getLastError()
Cursor
maximum value

50. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});
$lte
key.index
64-Bit Integer
Cursor