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. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
$pull
db.getLastError()
Object.bsonsize({document});
Cursor

2. Unique 12-byte ID for documents.
$pushAll
$gt
db.<collection>.findOne([properties]);
object id

3. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
$elemMatch
$nin
$ne
64-bit floating point numbers

4. 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
string
db.commandHelp("commandName")
Upsert

5. Query conditional allowing the selector to choose between more than one optional criteria.
$gte
Upsert
db.<collection>.findOne([properties]);
$or

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

7. command to start the mongo shell.
mongo
64-Bit Integer
$all
db.<col>.remove({selector});

8. Returns all the documents matching the optional properties.
db.<collection>.find([properties]);
$all
64-Bit Integer
date

9. 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 ] } } }
db.<collection>.findOne([properties]);
$pop
$addToSet
object id

10. 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 } }
Multi-updates
document
$push
binary data

11. A document contained by a parent document. The embedded document is a value of a key in the parent document.
binary data
object id
db.commandHelp("commandName")
embedded document

12. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});
db.<collection>.findOne([properties]);
$not
$addToSet
$lte

13. Stored as milliseconds since the epoch.
mongo
date
db.cloneDatabase(fromhost)
key.index

14. Returns help information for a command.
64-Bit Integer
null
show collections
db.commandHelp("commandName")

15. Meta query conditional used to negate the selector.
object id
$not
$all
db.getLastError()

16. changes the database on which you are working.
$lt
code
use <database name>
$addToSet

17. Updates all matching documents, not just the first, that match the selector.
use <database name>
db.runCommand({fsync:1,lock:1,async:1})
help
Multi-updates

18. The standard number representation in the javascript shell.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
64-bit floating point numbers
$pop
$rename

19. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
null
64-Bit Integer
mongo
32-Bit Integer

20. Update a document in the collection.
mongo
$unset
db.<col>.update({selector},{document});
$rename

21. Used to represent both a null value and a nonexistent field.
code
key.index
null
64-Bit Integer

22. 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.
$gte
db.getLastError()
$all
code

23. command to start the mongodb process.
db.myCollection.ensureIndex({keypattern},[{options}])
mongod
32-Bit Integer
db.<col>.help([commandName]);

24. Command to get help docs on a specific command at the collection level.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
db.<col>.help([commandName]);
$gte
db.<collection>.find([properties]);

25. Returns the size of a document after it is converted to BSON from the JSON-like original.
$size
$push
$set
Object.bsonsize({document});

26. Deletes documents from the collection based on the selector.
db.commandHelp("commandName")
db.<col>.remove({selector});
db.help([commandName]);
regular expression

27. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
db.commandHelp("commandName")
$gt
32-Bit Integer
null

28. Renames a field from the one indicated to the new field name. ex: { $rename : { old_field_name : new_field_name } }
Multi-updates
db.<collection>.find([properties]);
$rename
db.<collection>.insert({document});

29. Lists all the collections in the database in use.
array
show collections
64-Bit Integer
$in

30. set of UTF-8 characters.
$rename
$in
string
Object.bsonsize({document});

31. ...
batch insert
mongo
$size
$slice

32. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
undefined
$pullAll
$pull
Update Modifiers

33. 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.
$
db.commandHelp("commandName")
db.<collection>.insert({document});
Update Modifiers

34. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
Update Modifiers
Upsert
$slice
null

35. Operator allowing the partial specification of fields in an embedded document in an array.
$elemMatch
embedded document
$where
$

36. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
$nin
$lt
db.myCollection.ensureIndex({keypattern},[{options}])
use <database name>

37. Standard binary data type.
db.<collection>.find([properties]);
boolean
32-Bit Integer
64-Bit Integer

38. Adds a document to a collection.
db.cloneDatabase(fromhost)
db.<collection>.insert({document});
$pop
show collections

39. Set or list of values.
array
db.<collection>.insert({document});
db.<collection>.findOne([properties]);
$push

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

41. Javascript code. Documents can contain code as values.
code
db.<collection>.insert({document});
db.<col>.update({selector},{document});
Upsert

42. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
$set
Update Modifiers
db.getLastError()
db.<collection>.find([properties]);

43. 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.
$pushAll
date
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
64-Bit Integer

44. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
64-Bit Integer
mongod
$lt
$not

45. Binary-encoded serialization of mongo documents.
mongo
BSON
Multi-updates
64-Bit Integer

46. Command to list commands and descriptions of those commands in the context of the database.
db.cloneDatabase(fromhost)
$inc
$ne
help

47. 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
$lte
mongod
document

48. Command to get help docs on a specific command at the db level.
db.<col>.remove({selector});
Cursor
db.help([commandName]);
use <database name>

49. Standard javascript regular expressions. These can be stored in documents
mongod
db.commandHelp("commandName")
regular expression
$

50. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});
$ne
db.<collection>.find([properties]);
db.<collection>.findOne([properties]);
db.<collection>.insert({document});