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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. 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 } }
mongod
$pushAll
$where
$pop

2. Binary-encoded serialization of mongo documents.
$rename
BSON
$push
$gt

3. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
32-Bit Integer
$pushAll
$slice
db.<collection>.findOne([properties]);

4. 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.
array
$lt
Update Modifiers
db.<col>.help([commandName]);

5. Clone the current database (implied by 'db') from another host.
array
$or
$inc
db.cloneDatabase(fromhost)

6. Returns help information for a command.
Cursor
db.getLastError()
array
db.commandHelp("commandName")

7. 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 },
$unset
$where
document
$

8. command to start the mongo shell.
$gte
$all
mongo
db.<collection>.insert({document});

9. Command to get help docs on a specific command at the collection level.
use <database name>
$pullAll
db.cloneDatabase(fromhost)
db.<col>.help([commandName]);

10. 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.
$inc
$lte
db.runCommand({fsync:1,lock:1,async:1})
$mod

11. Returns one document matching the optional properties.
db.<collection>.findOne([properties]);
db.<collection>.find([properties]);
regular expression
mongod

12. 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.
db.<collection>.find([properties]);
null
$all
db.commandHelp("commandName")

13. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
$in
mongo
$nin
db.commandHelp("commandName")

14. Adds a document to a collection.
$size
$gte
db.<collection>.insert({document});
$slice

15. String of arbitrary bytes.
binary data
$elemMatch
maximum value
BSON

16. 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]);
db.commandHelp("commandName")
code
batch insert

17. Operator allowing the partial specification of fields in an embedded document in an array.
$elemMatch
$not
$where
$ne

18. Data structure used to store all other data in mongo databases.
$gte
null
document
$all

19. Command to get help docs on a specific command at the db level.
db.<col>.remove({selector});
boolean
$lt
db.help([commandName]);

20. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});
$nin
show collections
$ne
db.<col>.remove({selector});

21. Set or list of values.
Update Modifiers
null
db.<collection>.find([properties]);
array

22. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
$push
$slice
show collections
$gt

23. ...
$unset
batch insert
document
Cursor

24. Operator allowing the execution of arbitrary javascript as part of the selector.
$or
$where
mongod
db.runCommand({fsync:1,lock:1,async:1})

25. Clone the current database (implied by 'db') from another host.
boolean
$mod
db.commandHelp("commandName")
db.cloneDatabase(fromhost)

26. In BSON - represents the largest possible value.
maximum value
$push
$
$pull

27. Standard binary data type.
boolean
maximum value
$
binary data

28. Command to list commands and descriptions of those commands in the context of the database.
boolean
help
undefined
db.help([commandName]);

29. Javascript code. Documents can contain code as values.
db.<col>.update({selector},{document});
Multi-updates
key.index
code

30. command to start the mongo shell.
mongo
BSON
$all
embedded document

31. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
$inc
array
$pull
$push

32. Deletes a given field. ex: { $unset : { field : 1} }
$unset
mongo
Upsert
$addToSet

33. Lists all the collections in the database in use.
minimum value
show collections
db.runCommand({fsync:1,lock:1,async:1})
boolean

34. Adds a document to a collection.
db.<collection>.find([properties]);
$pull
regular expression
db.<collection>.insert({document});

35. Returns all the documents matching the optional properties.
db.<col>.remove({selector});
db.<collection>.find([properties]);
BSON
db.commandHelp("commandName")

36. Syntax used for selectors to be specific to a certain element position within an array.
regular expression
key.index
mongo
maximum value

37. 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 } }
$pop
code
$pull
$addToSet

38. set of UTF-8 characters.
$elemMatch
array
string
maximum value

39. Returns all the documents matching the optional properties.
$pullAll
db.<collection>.find([properties]);
$elemMatch
db.cloneDatabase(fromhost)

40. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
db.<col>.help([commandName]);
db.help([commandName]);
$lt
db.<collection>.insert({document});

41. Query conditional allowing the selector to choose between more than one optional criteria.
$or
$set
$in
db.<collection>.find([properties]);

42. Contains query conditional used to check if a value contains the field value.
$gte
key.index
$in
32-Bit Integer

43. changes the database on which you are working.
mongod
$
use <database name>
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);

44. Standard javascript regular expressions. These can be stored in documents
regular expression
array
Multi-updates
embedded document

45. Returns the size of a document after it is converted to BSON from the JSON-like original.
Object.bsonsize({document});
date
db.<col>.remove({selector});
string

46. Used to represent both a null value and a nonexistent field.
Update Modifiers
$slice
db.<col>.remove({selector});
null

47. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
show collections
$pullAll
binary data
$nin

48. A document contained by a parent document. The embedded document is a value of a key in the parent document.
$pullAll
db.<col>.remove({selector});
$set
embedded document

49. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
$addToSet
db.getLastError()
$gte
use <database name>

50. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
mongod
$slice
Cursor
db.<collection>.find([properties]);