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

2. 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.
$lte
$all
string
maximum value

3. Update a document in the collection.
$addToSet
db.<col>.update({selector},{document});
string
$unset

4. Adds a document to a collection.
code
db.<collection>.insert({document});
date
help

5. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
Update Modifiers
$lt
null
$

6. 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.
$gt
$rename
$mod
date

7. Returns one document matching the optional properties.
$elemMatch
maximum value
db.<collection>.findOne([properties]);
mongod

8. 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 } }
$nin
$pushAll
Multi-updates
regular expression

9. Meta query conditional used to negate the selector.
$unset
db.<collection>.insert({document});
$not
$

10. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
$lt
db.myCollection.ensureIndex({keypattern},[{options}])
$mod
$size

11. Query conditional allowing the selector to choose between more than one optional criteria.
32-Bit Integer
db.<collection>.findOne([properties]);
document
$or

12. 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 } }
$rename
$pop
binary data
64-Bit Integer

13. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$in
$pullAll
Object.bsonsize({document});

14. 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")
Update Modifiers
db.<col>.update({selector},{document});
null

15. Clone the current database (implied by 'db') from another host.
$in
regular expression
db.cloneDatabase(fromhost)
Multi-updates

16. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
key.index
$lte
Cursor
$nin

17. The standard number representation in the javascript shell.
$lt
64-bit floating point numbers
$lte
db.<collection>.insert({document});

18. 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.
Upsert
db.runCommand({fsync:1,lock:1,async:1})
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
show collections

19. Lists all the collections in the database in use.
$in
$where
$slice
show collections

20. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});
$lte
help
code
$nin

21. Renames a field from the one indicated to the new field name. ex: { $rename : { old_field_name : new_field_name } }
$lt
$rename
mongo
Cursor

22. Array specific conditional used to select based on the length or set-size of an array field value.
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$elemMatch
mongo
$size

23. Updates all matching documents, not just the first, that match the selector.
Multi-updates
mongod
key.index
$slice

24. String of arbitrary bytes.
$rename
binary data
$gte
$where

25. Command to list commands and descriptions of those commands in the context of the database.
help
Update Modifiers
db.<collection>.insert({document});
batch insert

26. Greater than query conditional. ex: db.<col>.find({numVal: {$gt:3}});
Multi-updates
$set
$pullAll
$gt

27. Clone the current database (implied by 'db') from another host.
$pushAll
$nin
regular expression
db.cloneDatabase(fromhost)

28. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}
db.<collection>.find([properties]);
$inc
code
Multi-updates

29. Returns help information for a command.
$
$lt
db.commandHelp("commandName")
Multi-updates

30. Operator allowing the execution of arbitrary javascript as part of the selector.
$not
batch insert
db.cloneDatabase(fromhost)
$where

31. changes the database on which you are working.
$pop
use <database name>
Cursor
string

32. In BSON - represents the largest possible value.
maximum value
null
$mod
db.<col>.remove({selector});

33. Stored as milliseconds since the epoch.
date
$pop
$pushAll
64-bit floating point numbers

34. Returns all the documents matching the optional properties.
db.<collection>.find([properties]);
undefined
db.<collection>.insert({document});
$addToSet

35. Returns the size of a document after it is converted to BSON from the JSON-like original.
$pullAll
$rename
$elemMatch
Object.bsonsize({document});

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

37. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
32-Bit Integer
$pull
db.<col>.remove({selector});
$lte

38. changes the database on which you are working.
BSON
$unset
object id
use <database name>

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

40. Data structure used to store all other data in mongo databases.
document
db.runCommand({fsync:1,lock:1,async:1})
$elemMatch
minimum value

41. Returns all the documents matching the optional properties.
binary data
$gt
db.<collection>.find([properties]);
object id

42. command to start the mongo shell.
Upsert
$or
mongo
$pop

43. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
$addToSet
db.<col>.help([commandName]);
$rename
$nin

44. Adds a document to a collection.
db.cloneDatabase(fromhost)
db.<col>.remove({selector});
db.<collection>.insert({document});
regular expression

45. Unique 12-byte ID for documents.
$ne
object id
db.help([commandName]);
string

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

47. command to start the mongodb process.
mongod
db.cloneDatabase(fromhost)
db.<collection>.find([properties]);
undefined

48. command to start the mongo shell.
Cursor
db.cloneDatabase(fromhost)
db.cloneDatabase(fromhost)
mongo

49. Standard binary data type.
$elemMatch
embedded document
boolean
use <database name>

50. Deletes a given field. ex: { $unset : { field : 1} }
$mod
key.index
$unset
$ne