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 binary data type.
maximum value
binary data
code
boolean

2. Returns one document matching the optional properties.
mongo
$size
db.<collection>.findOne([properties]);
$ne

3. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
db.getLastError()
db.<col>.update({selector},{document});
batch insert
$rename

4. Command to list commands and descriptions of those commands in the context of the database.
binary data
batch insert
64-bit floating point numbers
help

5. command to start the mongo shell.
mongo
batch insert
$elemMatch
$unset

6. In BSON - represents the smallest possible value.
embedded document
minimum value
$
$set

7. command to start the mongodb process.
$gte
64-Bit Integer
mongod
$rename

8. 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.
$elemMatch
$nin
$pullAll
Upsert

9. Standard javascript regular expressions. These can be stored in documents
regular expression
boolean
db.<col>.help([commandName]);
key.index

10. Lists all the collections in the database in use.
show collections
db.myCollection.ensureIndex({keypattern},[{options}])
binary data
$mod

11. command to start the mongodb process.
db.help([commandName]);
$rename
mongod
key.index

12. The standard number representation in the javascript shell.
db.<collection>.find([properties]);
Upsert
undefined
64-bit floating point numbers

13. Command to get help docs on a specific command at the db level.
db.help([commandName]);
$gt
$size
64-Bit Integer

14. In BSON - represents the largest possible value.
Object.bsonsize({document});
db.cloneDatabase(fromhost)
maximum value
db.<collection>.insert({document});

15. 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 },
help
$ne
$inc
$

16. Used to represent both a null value and a nonexistent field.
null
db.<collection>.insert({document});
maximum value
$where

17. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}
db.<collection>.insert({document});
show collections
$push
$inc

18. Set or list of values.
key.index
mongo
array
maximum value

19. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
$slice
db.<col>.remove({selector});
32-Bit Integer
db.<col>.remove({selector});

20. 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 ] } } }
boolean
db.<col>.remove({selector});
$size
$addToSet

21. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});
$ne
$addToSet
db.help([commandName]);
db.<collection>.insert({document});

22. Syntax used for selectors to be specific to a certain element position within an array.
db.commandHelp("commandName")
db.commandHelp("commandName")
$addToSet
key.index

23. Update a document in the collection.
date
db.<col>.update({selector},{document});
$pushAll
db.help([commandName]);

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

25. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
db.<collection>.findOne([properties]);
$or
regular expression
Cursor

26. Deletes documents from the collection based on the selector.
use <database name>
mongod
db.<col>.remove({selector});
db.<collection>.find([properties]);

27. Query conditional allowing the selector to choose between more than one optional criteria.
$or
$set
object id
db.<col>.update({selector},{document});

28. ...
$where
batch insert
Update Modifiers
minimum value

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

30. A document contained by a parent document. The embedded document is a value of a key in the parent document.
$mod
$nin
null
embedded document

31. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
mongod
Update Modifiers
db.myCollection.ensureIndex({keypattern},[{options}])
$gt

32. Deletes documents from the collection based on the selector.
db.<col>.remove({selector});
$push
batch insert
db.<col>.update({selector},{document});

33. 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.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
mongo
db.runCommand({fsync:1,lock:1,async:1})
batch insert

34. set of UTF-8 characters.
string
$in
show collections
help

35. Deletes a given field. ex: { $unset : { field : 1} }
$unset
db.help([commandName]);
db.<collection>.find([properties]);
db.runCommand({fsync:1,lock:1,async:1})

36. Returns help information for a command.
db.commandHelp("commandName")
Upsert
minimum value
embedded document

37. 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.
null
db.getLastError()
Update Modifiers
$pull

38. Greater than query conditional. ex: db.<col>.find({numVal: {$gt:3}});
$gt
db.commandHelp("commandName")
mongo
binary data

39. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});
batch insert
$gte
Update Modifiers
$lte

40. 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.
$addToSet
mongo
$mod
db.getLastError()

41. Adds a document to a collection.
64-bit floating point numbers
db.<collection>.insert({document});
db.<col>.update({selector},{document});
$ne

42. Meta query conditional used to negate the selector.
db.cloneDatabase(fromhost)
mongo
array
$not

43. Contains query conditional used to check if a value contains the field value.
Object.bsonsize({document});
date
$in
BSON

44. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
64-bit floating point numbers
boolean
db.getLastError()
32-Bit Integer

45. Binary-encoded serialization of mongo documents.
$gt
db.<collection>.insert({document});
BSON
db.<col>.remove({selector});

46. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
db.runCommand({fsync:1,lock:1,async:1})
$pullAll
$all
$inc

47. command to start the mongo shell.
document
mongo
db.<collection>.find([properties]);
date

48. Data structure used to store all other data in mongo databases.
$pullAll
$lte
document
undefined

49. Returns all the documents matching the optional properties.
$where
$pop
$in
db.<collection>.find([properties]);

50. Command to get help docs on a specific command at the collection level.
db.<col>.help([commandName]);
use <database name>
object id
db.myCollection.ensureIndex({keypattern},[{options}])