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

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.
mongod
$size
minimum value
$all

3. Updates all matching documents, not just the first, that match the selector.
$
document
64-Bit Integer
Multi-updates

4. 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 ] } } }
$not
$where
$addToSet
$lt

5. The standard number representation in the javascript shell.
64-bit floating point numbers
db.<collection>.find([properties]);
batch insert
db.<col>.update({selector},{document});

6. Not supported by the javascript shell and are converted to 64-bit floating point numbers.
string
date
$lte
32-Bit Integer

7. 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 } }
Cursor
$push
help
$not

8. Update modifier that set the value of a key and if the key does not exist, it will create the key. ex: db.<col>.update({selector},{"$set":{"someKey":"someValue"}});
$gte
$set
use <database name>
BSON

9. Command to list commands and descriptions of those commands in the context of the database.
help
$rename
db.<col>.help([commandName]);
key.index

10. Stored as milliseconds since the epoch.
$pop
date
$set
db.help([commandName]);

11. Operator allowing the execution of arbitrary javascript as part of the selector.
$where
db.cloneDatabase(fromhost)
$elemMatch
$lt

12. Clone the current database (implied by 'db') from another host.
db.<collection>.insert({document});
null
$nin
db.cloneDatabase(fromhost)

13. Returns all the documents matching the optional properties.
use <database name>
$inc
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
db.<collection>.find([properties]);

14. Returns information about the last operation. Not necessarily error data - the return can contain things like number of records updated.
$gte
$where
db.getLastError()
Object.bsonsize({document});

15. Standard binary data type.
$set
db.<collection>.insert({document});
boolean
use <database name>

16. 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.
undefined
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$mod
binary data

17. 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 } }
$pushAll
$unset
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$gt

18. command to start the mongodb process.
minimum value
db.myCollection.ensureIndex({keypattern},[{options}])
mongod
Upsert

19. 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.
$unset
Object.bsonsize({document});
db.<collection>.findOne([properties]);
Update Modifiers

20. Not equal query conditional. ex: db.<col>.find({numVal: {$ne:3}});
db.<col>.update({selector},{document});
$where
$ne
help

21. In BSON - represents the largest possible value.
$in
maximum value
db.<col>.update({selector},{document});
$push

22. Operator allowing the partial specification of fields in an embedded document in an array.
db.<col>.remove({selector});
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
32-Bit Integer
$elemMatch

23. The local variable representation of a query. Uniquely - the cursor does not hold the results but instead access to the results.
Cursor
db.<col>.update({selector},{document});
boolean
db.<col>.remove({selector});

24. Used to represent both a null value and a nonexistent field.
null
db.<collection>.find([properties]);
show collections
Object.bsonsize({document});

25. Less than or equal query conditional. ex: db.<col>.find({numVal: {$lte:3}});
minimum value
$lte
db.getLastError()
$pop

26. Greater than or equal query conditional. ex: db.<col>.find({numVal: {$gte:3}});
db.<col>.help([commandName]);
db.<collection>.insert({document});
$gte
key.index

27. command to start the mongodb process.
Object.bsonsize({document});
mongod
db.<collection>.insert({document});
$or

28. Meta query conditional used to negate the selector.
$not
$size
db.getLastError()
binary data

29. Removes all occurrences of a value from a field. ex: { $pull : { field : _value } }
binary data
$pull
help
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);

30. 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.
$or
db.copyDatabase(frmDBName, toDBName, [frmHostName], [user], [pwd]);
$set
db.<collection>.insert({document});

31. Less than query conditional. ex: db.<col>.find({numVal: {$lt:3}});
mongod
binary data
batch insert
$lt

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

33. Removes all occurrences of each value in the passed in array from the field. ex: { $pullAll : { field : value_array } }
$pullAll
undefined
$not
$inc

34. Does not contain query conditional used to select documents with the field that is not in the selector list of values.
db.<col>.remove({selector});
64-Bit Integer
db.<col>.update({selector},{document});
$nin

35. Creates an index on property(s). Options can describe the type of sorting, uniqueness, etc.
64-bit floating point numbers
Multi-updates
db.myCollection.ensureIndex({keypattern},[{options}])
db.<collection>.insert({document});

36. Array specific conditional used to select based on the length or set-size of an array field value.
help
$size
use <database name>
db.cloneDatabase(fromhost)

37. Greater than query conditional. ex: db.<col>.find({numVal: {$gt:3}});
$ne
regular expression
BSON
$gt

38. String of arbitrary bytes.
mongod
undefined
object id
binary data

39. Update a document in the collection.
db.<col>.remove({selector});
array
db.<col>.update({selector},{document});
binary data

40. In BSON - represents the smallest possible value.
document
db.<collection>.findOne([properties]);
$nin
minimum value

41. changes the database on which you are working.
binary data
Cursor
use <database name>
$pop

42. changes the database on which you are working.
batch insert
mongo
use <database name>
$pullAll

43. Syntax used for selectors to be specific to a certain element position within an array.
key.index
code
$where
db.<col>.remove({selector});

44. Contains query conditional used to check if a value contains the field value.
binary data
$unset
db.<collection>.find([properties]);
$in

45. Query conditional allowing the selector to choose between more than one optional criteria.
$not
$pullAll
array
$or

46. A document contained by a parent document. The embedded document is a value of a key in the parent document.
db.<col>.remove({selector});
Cursor
db.<col>.update({selector},{document});
embedded document

47. Adds a document to a collection.
$rename
$
db.<collection>.insert({document});
help

48. Returns help information for a command.
db.<collection>.find([properties]);
Object.bsonsize({document});
BSON
db.commandHelp("commandName")

49. Returns help information for a command.
db.commandHelp("commandName")
$gte
maximum value
$slice

50. Returns one document matching the optional properties.
db.<collection>.findOne([properties]);
$where
$addToSet
$set