DBCollection

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com.mongodb
Class DBCollection

java.lang.Object
  com.mongodb.DBCollection

public abstract class DBCollection
extends Object
extends Object

This class provides a skeleton implementation of a database collection.

A typical invocation sequence is thus

     Mongo mongo = new Mongo( new DBAddress( "localhost", 127017 ) );
     DB db = mongo.getDB( "mydb" );
     DBCollection collection = db.getCollection( "test" );

MongoDB Doc Links

collections

Field Summary
`protected String`	`_fullName`
`protected List<DBObject>`	`_hintFields`
`protected String`	`_name`
`protected Class`	`_objectClass`

Constructor Summary
`protected`	`DBCollection(DB base, String name)` Initializes a new collection.

Method Summary
`protected DBObject`	`_checkObject(DBObject o, boolean canBeNull, boolean query)`
`void`	`addOption(int option)` adds a default query option
`Object`	`apply(DBObject o)` calls `apply(com.mongodb.DBObject, boolean)` with ensureID=true
`Object`	`apply(DBObject jo, boolean ensureID)` calls `doapply(com.mongodb.DBObject)`, optionally adding an automatic _id field
`protected boolean`	`checkReadOnly(boolean strict)` Returns if this collection's database is read-only
`long`	`count()` returns the number of documents in this collection.
`long`	`count(DBObject query)` returns the number of documents that match a query.
`void`	`createIndex(DBObject keys)` calls `createIndex(com.mongodb.DBObject, com.mongodb.DBObject)` with default index options
`void`	`createIndex(DBObject keys, DBObject options)` Forces creation of an index on a set of fields, if one does not already exist.
`abstract void`	`createIndex(DBObject keys, DBObject options, DBEncoder encoder)` Forces creation of an index on a set of fields, if one does not already exist.
`List`	`distinct(String key)` find distinct values for a key
`List`	`distinct(String key, DBObject query)` find distinct values for a key
`protected abstract void`	`doapply(DBObject o)` Adds any necessary fields to a given object before saving it to the collection.
`void`	`drop()` Drops (deletes) this collection.
`void`	`dropIndex(DBObject keys)` Drops an index from this collection
`void`	`dropIndex(String name)` Drops an index from this collection
`void`	`dropIndexes()` Drops all indices from this collection
`void`	`dropIndexes(String name)` Drops an index from this collection
`void`	`ensureIndex(DBObject keys)` calls `ensureIndex(com.mongodb.DBObject, com.mongodb.DBObject)` with default options
`void`	`ensureIndex(DBObject keys, DBObject optionsIN)` Creates an index on a set of fields, if one does not already exist.
`void`	`ensureIndex(DBObject keys, String name)` calls `ensureIndex(com.mongodb.DBObject, java.lang.String, boolean)` with unique=false
`void`	`ensureIndex(DBObject keys, String name, boolean unique)` Ensures an index on this collection (that is, the index will be created if it does not exist).
`void`	`ensureIndex(String name)` Creates an ascending index on a field with default options, if one does not already exist.
`boolean`	`equals(Object o)`
`DBCursor`	`find()` Queries for all objects in this collection.
`DBCursor`	`find(DBObject ref)` Queries for an object in this collection.
`DBCursor`	`find(DBObject ref, DBObject keys)` Queries for an object in this collection.
`DBCursor`	`find(DBObject query, DBObject fields, int numToSkip, int batchSize)` Deprecated.
`DBCursor`	`find(DBObject query, DBObject fields, int numToSkip, int batchSize, int options)` Deprecated.
`DBObject`	`findAndModify(DBObject query, DBObject update)` calls `findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean)` with fields=null, sort=null, remove=false, returnNew=false, upsert=false
`DBObject`	`findAndModify(DBObject query, DBObject sort, DBObject update)` calls `findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean)` with fields=null, remove=false, returnNew=false, upsert=false
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert)` Finds the first document in the query and updates it.
`DBObject`	`findAndRemove(DBObject query)` calls `findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean)` with fields=null, sort=null, remove=true, returnNew=false, upsert=false
`DBObject`	`findOne()` Returns a single object from this collection.
`DBObject`	`findOne(DBObject o)` Returns a single object from this collection matching the query.
`DBObject`	`findOne(DBObject o, DBObject fields)` Returns a single object from this collection matching the query.
`DBObject`	`findOne(DBObject o, DBObject fields, ReadPreference readPref)` Returns a single object from this collection matching the query.
`DBObject`	`findOne(Object obj)` Finds an object by its id.
`DBObject`	`findOne(Object obj, DBObject fields)` Finds an object by its id.
`static String`	`genIndexName(DBObject keys)` Convenience method to generate an index name from the set of fields it is over.
`DBCollection`	`getCollection(String n)` Finds a collection that is prefixed with this collection's name.
`long`	`getCount()` calls `getCount(com.mongodb.DBObject, com.mongodb.DBObject)` with an empty query and null fields.
`long`	`getCount(DBObject query)` calls `getCount(com.mongodb.DBObject, com.mongodb.DBObject)` with null fields.
`long`	`getCount(DBObject query, DBObject fields)` calls `getCount(com.mongodb.DBObject, com.mongodb.DBObject, long, long)` with limit=0 and skip=0
`long`	`getCount(DBObject query, DBObject fields, long limit, long skip)` Returns the number of documents in the collection that match the specified query
`DB`	`getDB()` Returns the database this collection is a member of.
`DBDecoderFactory`	`getDBDecoderFactory()`
`DBEncoderFactory`	`getDBEncoderFactory()`
`String`	`getFullName()` Returns the full name of this collection, with the database name as a prefix.
`List<DBObject>`	`getIndexInfo()` Return a list of the indexes for this collection.
`protected Class`	`getInternalClass(String path)` gets the internal class
`String`	`getName()` Returns the name of this collection.
`Class`	`getObjectClass()` Gets the default class for objects in the collection
`int`	`getOptions()` gets the default query options
`ReadPreference`	`getReadPreference()` Gets the read preference
`CommandResult`	`getStats()` gets the collections statistics ("collstats" command)
`WriteConcern`	`getWriteConcern()` Get the write concern for this collection.
`DBObject`	`group(DBObject args)` Deprecated. prefer the `group(com.mongodb.GroupCommand)` which is more standard Applies a group operation
`DBObject`	`group(DBObject key, DBObject cond, DBObject initial, String reduce)` calls `group(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, java.lang.String, java.lang.String)` with finalize=null
`DBObject`	`group(DBObject key, DBObject cond, DBObject initial, String reduce, String finalize)` Applies a group operation
`DBObject`	`group(GroupCommand cmd)` Applies a group operation
`int`	`hashCode()`
`WriteResult`	`insert(DBObject... arr)` Saves document(s) to the database.
`WriteResult`	`insert(DBObject[] arr, WriteConcern concern)` Saves document(s) to the database.
`abstract WriteResult`	`insert(DBObject[] arr, WriteConcern concern, DBEncoder encoder)` Saves document(s) to the database.
`WriteResult`	`insert(DBObject o, WriteConcern concern)` Inserts a document into the database.
`WriteResult`	`insert(List<DBObject> list)` Saves document(s) to the database.
`WriteResult`	`insert(List<DBObject> list, WriteConcern concern)` Saves document(s) to the database.
`WriteResult`	`insert(WriteConcern concern, DBObject... arr)` Saves document(s) to the database.
`boolean`	`isCapped()` returns whether or not this is a capped collection
`MapReduceOutput`	`mapReduce(DBObject command)` performs a map reduce operation
`MapReduceOutput`	`mapReduce(MapReduceCommand command)` performs a map reduce operation
`MapReduceOutput`	`mapReduce(String map, String reduce, String outputTarget, DBObject query)` performs a map reduce operation Runs the command in REPLACE output mode (saves to named collection)
`MapReduceOutput`	`mapReduce(String map, String reduce, String outputTarget, MapReduceCommand.OutputType outputType, DBObject query)` performs a map reduce operation Specify an outputType to control job execution * INLINE - Return results inline * REPLACE - Replace the output collection with the job output * MERGE - Merge the job output with the existing contents of outputTarget * REDUCE - Reduce the job output with the existing contents of outputTarget
`WriteResult`	`remove(DBObject o)` calls `remove(com.mongodb.DBObject, com.mongodb.WriteConcern)` with the default WriteConcern
`WriteResult`	`remove(DBObject o, WriteConcern concern)` Removes objects from the database collection.
`abstract WriteResult`	`remove(DBObject o, WriteConcern concern, DBEncoder encoder)` Removes objects from the database collection.
`DBCollection`	`rename(String newName)` Calls `rename(java.lang.String, boolean)` with dropTarget=false
`DBCollection`	`rename(String newName, boolean dropTarget)` renames of this collection to newName
`void`	`resetIndexCache()` Clears all indices that have not yet been applied to this collection.
`void`	`resetOptions()` resets the default query options
`WriteResult`	`save(DBObject jo)` calls `save(com.mongodb.DBObject, com.mongodb.WriteConcern)` with default WriteConcern
`WriteResult`	`save(DBObject jo, WriteConcern concern)` Saves an object to this collection (does insert or update based on the object _id).
`void`	`setDBDecoderFactory(DBDecoderFactory fact)`
`void`	`setDBEncoderFactory(DBEncoderFactory fact)`
`void`	`setHintFields(List<DBObject> lst)` Set hint fields for this collection (to optimize queries).
`void`	`setInternalClass(String path, Class c)` sets the internal class
`void`	`setObjectClass(Class c)` Sets a default class for objects in this collection; null resets the class to nothing.
`void`	`setOptions(int options)` sets the default query options
`void`	`setReadPreference(ReadPreference preference)` Sets the read preference for this collection.
`void`	`setWriteConcern(WriteConcern concern)` Set the write concern for this collection.
`void`	`slaveOk()` Deprecated. Replaced with ReadPreference.SECONDARY
`String`	`toString()`
`WriteResult`	`update(DBObject q, DBObject o)` calls `update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean)` with upsert=false and multi=false
`WriteResult`	`update(DBObject q, DBObject o, boolean upsert, boolean multi)` calls `update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean, com.mongodb.WriteConcern)` with default WriteConcern.
`WriteResult`	`update(DBObject q, DBObject o, boolean upsert, boolean multi, WriteConcern concern)` Performs an update operation.
`abstract WriteResult`	`update(DBObject q, DBObject o, boolean upsert, boolean multi, WriteConcern concern, DBEncoder encoder)` Performs an update operation.
`WriteResult`	`updateMulti(DBObject q, DBObject o)` calls `update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean)` with upsert=false and multi=true

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Field Detail

_name

protected final String _name

_fullName

protected final String _fullName

_hintFields

protected List<DBObject> _hintFields

_objectClass

protected Class _objectClass

Constructor Detail

DBCollection

protected DBCollection(DB base,
                       String name)

Initializes a new collection. No operation is actually performed on the database.

Parameters:: base - database in which to create the collection; name - the name of the collection

Method Detail

insert

public WriteResult insert(DBObject[] arr,
                          WriteConcern concern)
                   throws MongoException

Saves document(s) to the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

arr - array of documents to save

concern - the write concern

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

insert

public abstract WriteResult insert(DBObject[] arr,
                                   WriteConcern concern,
                                   DBEncoder encoder)
                            throws MongoException

Saves document(s) to the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

arr - array of documents to save

concern - the write concern

encoder - the DBEncoder to use

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

insert

public WriteResult insert(DBObject o,
                          WriteConcern concern)
                   throws MongoException

Inserts a document into the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

o -

concern - the write concern

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

insert

public WriteResult insert(DBObject... arr)
                   throws MongoException

Saves document(s) to the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

arr - array of documents to save

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

insert

public WriteResult insert(WriteConcern concern,
                          DBObject... arr)
                   throws MongoException

Saves document(s) to the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

arr - array of documents to save

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

insert

public WriteResult insert(List<DBObject> list)
                   throws MongoException

Saves document(s) to the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

list - list of documents to save

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

insert

public WriteResult insert(List<DBObject> list,
                          WriteConcern concern)
                   throws MongoException

Saves document(s) to the database. if doc doesn't have an _id, one will be added you can get the _id that was added from doc after the insert

Parameters:

list - list of documents to save

concern - the write concern

Returns:

Throws:

MongoException

MongoDB Doc Links

insert

update

public WriteResult update(DBObject q,
                          DBObject o,
                          boolean upsert,
                          boolean multi,
                          WriteConcern concern)
                   throws MongoException

Performs an update operation.

Parameters:

q - search query for old object to update

o - object with which to update q

upsert - if the database should create the element if it does not exist

multi - if the update should be applied to all objects matching (db version 1.1.3 and above). An object will not be inserted if it does not exist in the collection and upsert=true and multi=true. See http://www.mongodb.org/display/DOCS/Atomic+Operations

concern - the write concern

Returns:

Throws:

MongoException

MongoDB Doc Links

update

update

public abstract WriteResult update(DBObject q,
                                   DBObject o,
                                   boolean upsert,
                                   boolean multi,
                                   WriteConcern concern,
                                   DBEncoder encoder)
                            throws MongoException

Performs an update operation.

Parameters:

q - search query for old object to update

o - object with which to update q

upsert - if the database should create the element if it does not exist

concern - the write concern

encoder - the DBEncoder to use

Returns:

Throws:

MongoException

MongoDB Doc Links

update

update

public WriteResult update(DBObject q,
                          DBObject o,
                          boolean upsert,
                          boolean multi)
                   throws MongoException

calls update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean, com.mongodb.WriteConcern) with default WriteConcern.

Parameters:

q - search query for old object to update

o - object with which to update q

upsert - if the database should create the element if it does not exist

multi - if the update should be applied to all objects matching (db version 1.1.3 and above) See http://www.mongodb.org/display/DOCS/Atomic+Operations

Returns:

Throws:

MongoException

MongoDB Doc Links

update

update

public WriteResult update(DBObject q,
                          DBObject o)
                   throws MongoException

calls update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean) with upsert=false and multi=false

Parameters:

q - search query for old object to update

o - object with which to update q

Returns:

Throws:

MongoException

MongoDB Doc Links

update

updateMulti

public WriteResult updateMulti(DBObject q,
                               DBObject o)
                        throws MongoException

calls update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean) with upsert=false and multi=true

Parameters:

q - search query for old object to update

o - object with which to update q

Returns:

Throws:

MongoException

MongoDB Doc Links

update

doapply

protected abstract void doapply(DBObject o)

Adds any necessary fields to a given object before saving it to the collection.

Parameters:: o - object to which to add the fields

remove

public WriteResult remove(DBObject o,
                          WriteConcern concern)
                   throws MongoException

Removes objects from the database collection.

Parameters:

o - the object that documents to be removed must match

concern - WriteConcern for this operation

Returns:

Throws:

MongoException

MongoDB Doc Links

remove

remove

public abstract WriteResult remove(DBObject o,
                                   WriteConcern concern,
                                   DBEncoder encoder)
                            throws MongoException

Removes objects from the database collection.

Parameters:

o - the object that documents to be removed must match

concern - WriteConcern for this operation

encoder - the DBEncoder to use

Returns:

Throws:

MongoException

MongoDB Doc Links

remove

remove

public WriteResult remove(DBObject o)
                   throws MongoException

calls remove(com.mongodb.DBObject, com.mongodb.WriteConcern) with the default WriteConcern

Parameters:

o - the object that documents to be removed must match

Returns:

Throws:

MongoException

MongoDB Doc Links

remove

find

@Deprecated
public final DBCursor find(DBObject query,
                                      DBObject fields,
                                      int numToSkip,
                                      int batchSize,
                                      int options)
                    throws MongoException

Deprecated.

Calls find(com.mongodb.DBObject, com.mongodb.DBObject, int, int) and applies the query options

Parameters:

query - query used to search

fields - the fields of matching objects to return

numToSkip - number of objects to skip

batchSize - the batch size. This option has a complex behavior, see DBCursor.batchSize(int)

options - - see Bytes QUERYOPTION_*

Returns:

the cursor

Throws:

MongoException

MongoDB Doc Links

find

find

@Deprecated
public final DBCursor find(DBObject query,
                                      DBObject fields,
                                      int numToSkip,
                                      int batchSize)

Deprecated.

Finds objects from the database that match a query. A DBCursor object is returned, that can be iterated to go through the results.

Parameters:

query - query used to search

fields - the fields of matching objects to return

numToSkip - number of objects to skip

batchSize - the batch size. This option has a complex behavior, see DBCursor.batchSize(int)

Returns:

the cursor

Throws:

MongoException

MongoDB Doc Links

find

findOne

public final DBObject findOne(Object obj)
                       throws MongoException

Finds an object by its id. This compares the passed in value to the _id field of the document

Parameters:: obj - any valid object
Returns:: the object, if found, otherwise null
Throws:: MongoException

findOne

public final DBObject findOne(Object obj,
                              DBObject fields)

Finds an object by its id. This compares the passed in value to the _id field of the document

Parameters:

obj - any valid object

fields - fields to return

Returns:

the object, if found, otherwise null

MongoDB Doc Links

find

findAndModify

public DBObject findAndModify(DBObject query,
                              DBObject fields,
                              DBObject sort,
                              boolean remove,
                              DBObject update,
                              boolean returnNew,
                              boolean upsert)

Finds the first document in the query and updates it.

Parameters:: query - query to match; fields - fields to be returned; sort - sort to apply before picking first document; remove - if true, document found will be removed; update - update to apply; returnNew - if true, the updated document is returned, otherwise the old document is returned (or it would be lost forever); upsert - do upsert (insert if document not present)
Returns:: the document

findAndModify

public DBObject findAndModify(DBObject query,
                              DBObject sort,
                              DBObject update)

calls

findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean)

with fields=null, remove=false, returnNew=false, upsert=false

Parameters:: query -; sort -; update -
Returns:: the old document

findAndModify

public DBObject findAndModify(DBObject query,
                              DBObject update)

calls

findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean)

with fields=null, sort=null, remove=false, returnNew=false, upsert=false

Parameters:: query -; update -
Returns:: the old document

findAndRemove

public DBObject findAndRemove(DBObject query)

calls

findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean)

with fields=null, sort=null, remove=true, returnNew=false, upsert=false

Parameters:: query -
Returns:: the removed document

createIndex

public final void createIndex(DBObject keys)
                       throws MongoException

calls createIndex(com.mongodb.DBObject, com.mongodb.DBObject) with default index options

Parameters:: keys - an object with a key set of the fields desired for the index
Throws:: MongoException

createIndex

public void createIndex(DBObject keys,
                        DBObject options)
                 throws MongoException

Forces creation of an index on a set of fields, if one does not already exist.

Parameters:: keys -; options -
Throws:: MongoException

createIndex

public abstract void createIndex(DBObject keys,
                                 DBObject options,
                                 DBEncoder encoder)
                          throws MongoException

Forces creation of an index on a set of fields, if one does not already exist.

Parameters:: keys -; options -; encoder - the DBEncoder to use
Throws:: MongoException

ensureIndex

public final void ensureIndex(String name)

Creates an ascending index on a field with default options, if one does not already exist.

Parameters:: name - name of field to index on

ensureIndex

public final void ensureIndex(DBObject keys)
                       throws MongoException

calls ensureIndex(com.mongodb.DBObject, com.mongodb.DBObject) with default options

Parameters:: keys - an object with a key set of the fields desired for the index
Throws:: MongoException

ensureIndex

public void ensureIndex(DBObject keys,
                        String name)
                 throws MongoException

calls ensureIndex(com.mongodb.DBObject, java.lang.String, boolean) with unique=false

Parameters:

keys - fields to use for index

name - an identifier for the index

Throws:

MongoException

MongoDB Doc Links

indexes

ensureIndex

public void ensureIndex(DBObject keys,
                        String name,
                        boolean unique)
                 throws MongoException

Ensures an index on this collection (that is, the index will be created if it does not exist).

Parameters:: keys - fields to use for index; name - an identifier for the index. If null or empty, the default name will be used.; unique - if the index should be unique
Throws:: MongoException

ensureIndex

public final void ensureIndex(DBObject keys,
                              DBObject optionsIN)
                       throws MongoException

Creates an index on a set of fields, if one does not already exist.

Parameters:: keys - an object with a key set of the fields desired for the index; optionsIN - options for the index (name, unique, etc)
Throws:: MongoException

resetIndexCache

public void resetIndexCache()

Clears all indices that have not yet been applied to this collection.

genIndexName

public static String genIndexName(DBObject keys)

Convenience method to generate an index name from the set of fields it is over.

Parameters:: keys - the names of the fields used in this index
Returns:: a string representation of this index's fields

setHintFields

public void setHintFields(List<DBObject> lst)

Set hint fields for this collection (to optimize queries).

Parameters:: lst - a list of DBObjects to be used as hints

find

public final DBCursor find(DBObject ref)

Queries for an object in this collection.

Parameters:

ref - object for which to search

Returns:

an iterator over the results

MongoDB Doc Links

find

find

public final DBCursor find(DBObject ref,
                           DBObject keys)

Queries for an object in this collection.

An empty DBObject will match every document in the collection. Regardless of fields specified, the _id fields are always returned.

An example that returns the "x" and "_id" fields for every document in the collection that has an "x" field:

 BasicDBObject keys = new BasicDBObject();
 keys.put("x", 1);

 DBCursor cursor = collection.find(new BasicDBObject(), keys);

Parameters:

ref - object for which to search

keys - fields to return

Returns:

a cursor to iterate over results

MongoDB Doc Links

find

find

public final DBCursor find()

Queries for all objects in this collection.

Returns:

a cursor which will iterate over every object

MongoDB Doc Links

find

findOne

public final DBObject findOne()
                       throws MongoException

Returns a single object from this collection.

Returns:: the object found, or null if the collection is empty
Throws:: MongoException

findOne

public final DBObject findOne(DBObject o)
                       throws MongoException

Returns a single object from this collection matching the query.

Parameters:: o - the query object
Returns:: the object found, or null if no such object exists
Throws:: MongoException

findOne

public final DBObject findOne(DBObject o,
                              DBObject fields)

Returns a single object from this collection matching the query.

Parameters:

o - the query object

fields - fields to return

Returns:

the object found, or null if no such object exists

MongoDB Doc Links

find

findOne

public final DBObject findOne(DBObject o,
                              DBObject fields,
                              ReadPreference readPref)

Returns a single object from this collection matching the query.

Parameters:

o - the query object

fields - fields to return

Returns:

the object found, or null if no such object exists

MongoDB Doc Links

find

apply

public final Object apply(DBObject o)

calls apply(com.mongodb.DBObject, boolean) with ensureID=true

Parameters:: o - DBObject to which to add fields
Returns:: the modified parameter object

apply

public final Object apply(DBObject jo,
                          boolean ensureID)

calls doapply(com.mongodb.DBObject), optionally adding an automatic _id field

Parameters:: jo - object to add fields to; ensureID - whether to add an _id field
Returns:: the modified object o

save

public final WriteResult save(DBObject jo)

calls save(com.mongodb.DBObject, com.mongodb.WriteConcern) with default WriteConcern

Parameters:: jo - the DBObject to save will add _id field to jo if needed
Returns:

save

public final WriteResult save(DBObject jo,
                              WriteConcern concern)
                       throws MongoException

Saves an object to this collection (does insert or update based on the object _id).

Parameters:: jo - the DBObject to save; concern - the write concern
Returns:
Throws:: MongoException

dropIndexes

public void dropIndexes()
                 throws MongoException

Drops all indices from this collection

Throws:: MongoException

dropIndexes

public void dropIndexes(String name)
                 throws MongoException

Drops an index from this collection

Parameters:: name - the index name
Throws:: MongoException

drop

public void drop()
          throws MongoException

Drops (deletes) this collection. Use with care.

Throws:: MongoException

count

public long count()
           throws MongoException

returns the number of documents in this collection.

Returns:
Throws:: MongoException

count

public long count(DBObject query)
           throws MongoException

returns the number of documents that match a query.

Parameters:: query - query to match
Returns:
Throws:: MongoException

getCount

public long getCount()
              throws MongoException

calls getCount(com.mongodb.DBObject, com.mongodb.DBObject) with an empty query and null fields.

Returns:: number of documents that match query
Throws:: MongoException

getCount

public long getCount(DBObject query)
              throws MongoException

calls getCount(com.mongodb.DBObject, com.mongodb.DBObject) with null fields.

Parameters:: query - query to match
Returns:
Throws:: MongoException

getCount

public long getCount(DBObject query,
                     DBObject fields)
              throws MongoException

calls getCount(com.mongodb.DBObject, com.mongodb.DBObject, long, long) with limit=0 and skip=0

Parameters:: query - query to match; fields - fields to return
Returns:
Throws:: MongoException

getCount

public long getCount(DBObject query,
                     DBObject fields,
                     long limit,
                     long skip)
              throws MongoException

Returns the number of documents in the collection that match the specified query

Parameters:: query - query to select documents to count; fields - fields to return; limit - limit the count to this value; skip - number of entries to skip
Returns:: number of documents that match query and fields
Throws:: MongoException

rename

public DBCollection rename(String newName)
                    throws MongoException

Calls rename(java.lang.String, boolean) with dropTarget=false

Parameters:: newName - new collection name (not a full namespace)
Returns:: the new collection
Throws:: MongoException

rename

public DBCollection rename(String newName,
                           boolean dropTarget)
                    throws MongoException

renames of this collection to newName

Parameters:: newName - new collection name (not a full namespace); dropTarget - if a collection with the new name exists, whether or not to drop it
Returns:: the new collection
Throws:: MongoException

group

public DBObject group(DBObject key,
                      DBObject cond,
                      DBObject initial,
                      String reduce)
               throws MongoException

calls group(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, java.lang.String, java.lang.String) with finalize=null

Parameters:: key - - { a : true }; cond - - optional condition on query; reduce - javascript reduce function; initial - initial value for first match on a key
Returns:
Throws:: MongoException
See Also:: http://www.mongodb.org/display/DOCS/Aggregation

group

public DBObject group(DBObject key,
                      DBObject cond,
                      DBObject initial,
                      String reduce,
                      String finalize)
               throws MongoException

Applies a group operation

Parameters:: key - - { a : true }; cond - - optional condition on query; reduce - javascript reduce function; initial - initial value for first match on a key; finalize - An optional function that can operate on the result(s) of the reduce function.
Returns:
Throws:: MongoException
See Also:: http://www.mongodb.org/display/DOCS/Aggregation

group

public DBObject group(GroupCommand cmd)

Applies a group operation

Parameters:: cmd - the group command
Returns:
Throws:: MongoException
See Also:: http://www.mongodb.org/display/DOCS/Aggregation

group

@Deprecated
public DBObject group(DBObject args)
               throws MongoException

Deprecated. prefer the group(com.mongodb.GroupCommand) which is more standard Applies a group operation

Parameters:: args - object representing the arguments to the group function
Returns:
Throws:: MongoException
See Also:: http://www.mongodb.org/display/DOCS/Aggregation

distinct

public List distinct(String key)

find distinct values for a key

Parameters:: key -
Returns:

distinct

public List distinct(String key,
                     DBObject query)

find distinct values for a key

Parameters:: key -; query - query to match
Returns:

mapReduce

public MapReduceOutput mapReduce(String map,
                                 String reduce,
                                 String outputTarget,
                                 DBObject query)
                          throws MongoException

performs a map reduce operation Runs the command in REPLACE output mode (saves to named collection)

Parameters:

map - map function in javascript code

outputTarget - optional - leave null if want to use temp collection

reduce - reduce function in javascript code

query - to match

Returns:

Throws:

MongoException

MongoDB Doc Links

mapreduce

mapReduce

public MapReduceOutput mapReduce(String map,
                                 String reduce,
                                 String outputTarget,
                                 MapReduceCommand.OutputType outputType,
                                 DBObject query)
                          throws MongoException

performs a map reduce operation Specify an outputType to control job execution * INLINE - Return results inline * REPLACE - Replace the output collection with the job output * MERGE - Merge the job output with the existing contents of outputTarget * REDUCE - Reduce the job output with the existing contents of outputTarget

Parameters:

map - map function in javascript code

outputTarget - optional - leave null if want to use temp collection

outputType - set the type of job output

reduce - reduce function in javascript code

query - to match

Returns:

Throws:

MongoException

MongoDB Doc Links

mapreduce

mapReduce

public MapReduceOutput mapReduce(MapReduceCommand command)
                          throws MongoException

performs a map reduce operation

Parameters:: command - object representing the parameters
Returns:
Throws:: MongoException

mapReduce

public MapReduceOutput mapReduce(DBObject command)
                          throws MongoException

performs a map reduce operation

Parameters:: command - object representing the parameters
Returns:
Throws:: MongoException

getIndexInfo

public List<DBObject> getIndexInfo()

Return a list of the indexes for this collection. Each object in the list is the "info document" from MongoDB

Returns:: list of index documents

dropIndex

public void dropIndex(DBObject keys)
               throws MongoException

Drops an index from this collection

Parameters:: keys - keys of the index
Throws:: MongoException

dropIndex

public void dropIndex(String name)
               throws MongoException

Drops an index from this collection

Parameters:: name - name of index to drop
Throws:: MongoException

getStats

public CommandResult getStats()

gets the collections statistics ("collstats" command)

Returns:

isCapped

public boolean isCapped()

returns whether or not this is a capped collection

Returns:

_checkObject

protected DBObject _checkObject(DBObject o,
                                boolean canBeNull,
                                boolean query)

getCollection

public DBCollection getCollection(String n)

Finds a collection that is prefixed with this collection's name. A typical use of this might be

    DBCollection users = mongo.getCollection( "wiki" ).getCollection( "users" );

Which is equivalent to


   DBCollection users = mongo.getCollection( "wiki.users" );

Parameters:: n - the name of the collection to find
Returns:: the matching collection

getName

public String getName()

Returns the name of this collection.

Returns:: the name of this collection

getFullName

public String getFullName()

Returns the full name of this collection, with the database name as a prefix.

Returns:: the name of this collection

getDB

public DB getDB()

Returns the database this collection is a member of.

Returns:: this collection's database

checkReadOnly

protected boolean checkReadOnly(boolean strict)

Returns if this collection's database is read-only

Parameters:: strict - if an exception should be thrown if the database is read-only
Returns:: if this collection's database is read-only
Throws:: RuntimeException - if the database is read-only and strict is set

hashCode

public int hashCode()

Overrides:: hashCode in class Object

equals

public boolean equals(Object o)

Overrides:: equals in class Object

toString

public String toString()

Overrides:: toString in class Object

setObjectClass

public void setObjectClass(Class c)

Sets a default class for objects in this collection; null resets the class to nothing.

Parameters:: c - the class
Throws:: IllegalArgumentException - if c is not a DBObject

getObjectClass

public Class getObjectClass()

Gets the default class for objects in the collection

Returns:: the class

setInternalClass

public void setInternalClass(String path,
                             Class c)

sets the internal class

Parameters:: path -; c -

getInternalClass

protected Class getInternalClass(String path)

gets the internal class

Parameters:: path -
Returns:

setWriteConcern

public void setWriteConcern(WriteConcern concern)

Set the write concern for this collection. Will be used for writes to this collection. Overrides any setting of write concern at the DB level. See the documentation for WriteConcern for more information.

Parameters:: concern - write concern to use

getWriteConcern

public WriteConcern getWriteConcern()

Get the write concern for this collection.

Returns:

setReadPreference

public void setReadPreference(ReadPreference preference)

Sets the read preference for this collection. Will be used as default for reads from this collection; overrides DB & Connection level settings. See the * documentation for ReadPreference for more information.

Parameters:: preference - Read Preference to use

getReadPreference

public ReadPreference getReadPreference()

Gets the read preference

Returns:

slaveOk

@Deprecated
public void slaveOk()

Deprecated. Replaced with ReadPreference.SECONDARY

makes this query ok to run on a slave node

See Also:: com.mongodb.ReadPreference.SECONDARY

addOption

public void addOption(int option)

adds a default query option

Parameters:: option -

setOptions

public void setOptions(int options)

sets the default query options

Parameters:: options -

resetOptions

public void resetOptions()

resets the default query options

getOptions

public int getOptions()

gets the default query options

Returns:

setDBDecoderFactory

public void setDBDecoderFactory(DBDecoderFactory fact)

getDBDecoderFactory

public DBDecoderFactory getDBDecoderFactory()

setDBEncoderFactory

public void setDBEncoderFactory(DBEncoderFactory fact)

getDBEncoderFactory

public DBEncoderFactory getDBEncoderFactory()

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com.mongodb Class DBCollection

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DBCollection

insert

insert

insert

insert

insert

insert

insert

update

update

update

update

updateMulti

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remove

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resetIndexCache

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find

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dropIndexes

dropIndexes

drop

count

count

getCount

getCount

getCount

getCount

rename

rename

group

group

group

group

distinct

distinct

mapReduce

mapReduce

mapReduce

mapReduce

getIndexInfo

dropIndex

dropIndex

getStats

isCapped

_checkObject

getCollection

com.mongodb
Class DBCollection