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- MongoDB\Collection::count()
MongoDB\Collection::count()
Deprecated since version 1.4.
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Definition
-
MongoDB\Collection::count
Count the number of documents that match the filter criteria.
This method has the following parameters:
Parameter Type Description $filter
array|object Optional. The filter criteria that specifies the documents to count. $options
array Optional. An array specifying the desired options. The
$options
parameter supports the following options:Option Type Description collation
array|object Optional. Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks. When specifying collation, the
locale
field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document.If the collation is unspecified but the collection has a default collation, the operation uses the collation specified for the collection. If no collation is specified for the collection or for the operation, MongoDB uses the simple binary comparison used in prior versions for string comparisons.
comment
mixed Optional. Enables users to specify an arbitrary comment to help trace the operation through the database profiler, currentOp output, and logs.
This is not supported for server versions prior to 4.4 and will result in an exception at execution time if used.
New in version 1.13.
hint
string|array|object Optional. The index to use. Specify either the index name as a string or the index key pattern as a document. If specified, then the query system will only consider plans using the hinted index.
Changed in version 1.2: If a document is provided, it is passed to the command as-is. Previously, the library would convert the key pattern to an index name.
limit
integer Optional. The maximum number of matching documents to return. maxTimeMS
integer Optional. The cumulative time limit in milliseconds for processing operations on the cursor. MongoDB aborts the operation at the earliest following interrupt point. readConcern
MongoDB\Driver\ReadConcern Optional. Read concern to use for the operation. Defaults to the collection’s read concern.
It is not possible to specify a read concern for individual operations as part of a transaction. Instead, set the
readConcern
option when starting the transaction with startTransaction.readPreference
MongoDB\Driver\ReadPreference Optional. Read preference to use for the operation. Defaults to the collection’s read preference. session
MongoDB\Driver\Session Optional. Client session to associate with the operation.
New in version 1.3.
skip
integer Optional. The number of matching documents to skip before returning results.
Return Values
The number of documents matching the filter criteria.
Errors/Exceptions
MongoDB\Exception\UnexpectedValueException
if the command
response from the server was malformed.
MongoDB\Exception\UnsupportedException
if options are used and
not supported by the selected server (e.g. collation
, readConcern
,
writeConcern
).
MongoDB\Exception\InvalidArgumentException
for errors related to
the parsing of parameters or options.
MongoDB\Driver\Exception\RuntimeException for other errors at the driver level (e.g. connection errors).
Behavior
This method is deprecated and cannot be executed within a transaction. It has
always been implemented using the count
command. The behavior of the count
command differs depending on the options
passed to it and may or may not provide an accurate count. When no query filter
is provided, the count
command provides an estimate using collection
metadata. Even when provided with a query filter the count
command can
return inaccurate results with a sharded cluster if orphaned documents exist or
if a chunk migration is in progress. The
MongoDB\Collection::countDocuments()
method avoids these sharded
cluster problems entirely.
When evaluating query criteria, MongoDB compares types and values according to its own comparison rules for BSON types, which differs from PHP’s comparison and type juggling rules. When matching a special BSON type the query criteria should use the respective BSON class in the driver (e.g. use MongoDB\BSON\ObjectId to match an ObjectId).
See Also
- count command reference in the MongoDB manual
MongoDB\Collection::countDocuments()
MongoDB\Collection::estimatedDocumentCount()