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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. command to start the mongo shell.
mongo
mongod
db.getLastError()
boolean

2. Operator allowing the execution of arbitrary javascript as part of the selector.
64-Bit Integer
$where
$lte
$pullAll

3. command to start the mongo shell.
db.<col>.remove({selector});
mongo
date
mongod

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.
$push
minimum value
key.index
Update Modifiers

5. 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 ] } } }
$nin
db.cloneDatabase(fromhost)
binary data
$addToSet

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

7. set of UTF-8 characters.
string
$pullAll
db.<collection>.find([properties]);
$slice

8. Lists all the collections in the database in use.
show collections
$addToSet
boolean
undefined

9. Used to describe a variable as not having been initialized.
maximum value
undefined
boolean
mongod

10. Deletes documents from the collection based on the selector.
db.<col>.remove({selector});
$addToSet
show collections
db.<collection>.find([properties]);

11. Javascript code. Documents can contain code as values.
$unset
Upsert
$pullAll
code

12. Deletes a given field. ex: { $unset : { field : 1} }
$where
$unset
Update Modifiers
show collections

13. A document contained by a parent document. The embedded document is a value of a key in the parent document.
embedded document
64-bit floating point numbers
$push
db.<collection>.insert({document});

14. changes the database on which you are working.
use <database name>
db.<col>.update({selector},{document});
db.<collection>.insert({document});
db.<collection>.findOne([properties]);

15. Contains query conditional used to check if a value contains the field value.
db.<col>.remove({selector});
$set
32-Bit Integer
$in

16. 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
$unset
db.commandHelp("commandName")
use <database name>

17. Stored as milliseconds since the epoch.
date
$nin
$rename
$mod

18. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
64-Bit Integer
db.<collection>.findOne([properties]);
code
$lt

19. 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.
regular expression
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$pullAll
$addToSet

20. Operator used in the second argument of the find() call to specify which slice of an array to return for an array field.
db.<collection>.find([properties]);
$slice
Upsert
db.getLastError()

21. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
document
$gte
$nin
Object.bsonsize({document});

22. Greater than query conditional. ex: db.<col>.find({numVal: {$gt:3}});
BSON
$gt
db.<col>.update({selector},{document});
db.<col>.remove({selector});

23. 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.cloneDatabase(fromhost)
db.commandHelp("commandName")
regular expression

24. Returns one document matching the optional properties.
object id
db.<col>.remove({selector});
mongod
db.<collection>.findOne([properties]);

25. Meta query conditional used to negate the selector.
$not
db.commandHelp("commandName")
Cursor
Upsert

26. Returns the size of a document after it is converted to BSON from the JSON-like original.
$addToSet
regular expression
document
Object.bsonsize({document});

27. Adds a document to a collection.
$or
db.<collection>.insert({document});
$elemMatch
BSON

28. Greater than or equal query conditional. ex: db.<col>.find({numVal: {$gte:3}});
db.commandHelp("commandName")
$gte
batch insert
Object.bsonsize({document});

29. Update a document in the collection.
db.<col>.update({selector},{document});
$set
batch insert
object id

30. Command to get help docs on a specific command at the collection level.
$rename
$pullAll
db.<col>.help([commandName]);
64-Bit Integer

31. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
string
db.<col>.remove({selector});
$pullAll
use <database name>

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

33. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
$or
$gt
db.getLastError()
$pull

34. 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 } }
minimum value
use <database name>
$push
db.commandHelp("commandName")

35. Clone the current database (implied by 'db') from another host.
db.cloneDatabase(fromhost)
db.<col>.remove({selector});
64-Bit Integer
db.commandHelp("commandName")

36. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
use <database name>
Cursor
$ne
$size

37. Update modifier used to increment a value. ex: {"$inc":{"counter":2}}
$inc
$elemMatch
$mod
db.myCollection.ensureIndex({keypattern},[{options}])

38. 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 } }
db.commandHelp("commandName")
object id
$mod
$pushAll

39. Deletes documents from the collection based on the selector.
$unset
db.<col>.remove({selector});
db.runCommand({fsync:1,lock:1,async:1})
db.getLastError()

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.
$lt
$inc
db.cloneDatabase(fromhost)
$mod

41. Standard binary data type.
$gt
boolean
$unset
Upsert

42. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
$pullAll
db.myCollection.ensureIndex({keypattern},[{options}])
$or
64-Bit Integer

43. Command to get help docs on a specific command at the db level.
db.help([commandName]);
null
db.<col>.remove({selector});
date

44. The standard number representation in the javascript shell.
maximum value
64-bit floating point numbers
regular expression
embedded document

45. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
db.<collection>.findOne([properties]);
db.<collection>.find([properties]);
$pull
db.commandHelp("commandName")

46. Updates all matching documents, not just the first, that match the selector.
document
mongo
Multi-updates
string

47. In BSON - represents the smallest possible value.
code
db.getLastError()
db.commandHelp("commandName")
minimum value

48. Query conditional allowing the selector to choose between more than one optional criteria.
$or
$lt
regular expression
$gte

49. Returns all the documents matching the optional properties.
$elemMatch
null
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
db.<collection>.find([properties]);

50. Array specific conditional used to select based on the length or set-size of an array field value.
db.myCollection.ensureIndex({keypattern},[{options}])
$size
show collections
db.<collection>.find([properties]);