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- MongoDB\Database::createCollection()
MongoDB\Database::createCollection()
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Definition
-
MongoDB\Database::createCollection
Explicitly creates a collection.
MongoDB creates collections implicitly when you first reference the collection in a command, such as when inserting a document into a new collection. You may also explicitly create a collection with specific options using the
MongoDB\Database::createCollection()
method, or using db.createCollection() in the mongo shell.Explicitly creating collections enables you to create capped collections, specify document validation criteria, or configure your storage engine or indexing options.
This method has the following parameters:
Parameter Type Description $collectionName
string The name of the collection to create. $options
array Optional. An array specifying the desired options. The
$options
parameter supports the following options:Option Type Description autoIndexId
boolean Optional. Specify
false
to disable the automatic creation of an index on the_id
field.Important
For replica sets, do not set
autoIndexId
tofalse
.Deprecated since version 3.2.: The
autoIndexId
option will be removed in MongoDB 3.4.capped
boolean Optional. To create a capped collection, specify true
. If you specifytrue
, you must also set a maximum size in thesize
option.collation
array|object Optional. Specifies the collation for the collection.
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.
This option is available in MongoDB 3.4+ and will result in an exception at execution time if specified for an older server version.
flags
integer Optional. Available for the MMAPv1 storage engine only to set the
usePowerOf2Sizes
andnoPadding
flags.The MongoDB PHP Library provides constants that you can combine with a bitwise OR operator to set the flag values:
MongoDB\Operation\CreateCollection::USE_POWER_OF_2_SIZES
:1
MongoDB\Operation\CreateCollection::NO_PADDING
:2
Defaults to
1
.Note
MongoDB 3.0 and later ignores the
usePowerOf2Sizes
flag. See collMod and db.createCollection() for more information.indexOptionDefaults
array|object Optional. Allows users to specify a default configuration for indexes when creating a collection.
The
indexOptionDefaults
option accepts astorageEngine
document, which should take the following form:{ <storage-engine-name>: <options> }
Storage engine configurations specified when creating indexes are validated and logged to the oplog during replication to support replica sets with members that use different storage engines.
max
integer Optional. The maximum number of documents allowed in the capped collection. The size
option takes precedence over this limit. If a capped collection reaches thesize
limit before it reaches the maximum number of documents, MongoDB removes old documents. If you prefer to use themax
limit, ensure that thesize
limit, which is required for a capped collection, is sufficient to contain the maximum number of documents.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. size
integer Optional. Specify a maximum size in bytes for a capped collection. Once a capped collection reaches its maximum size, MongoDB removes the older documents to make space for the new documents. The size
option is required for capped collections and ignored for other collections.storageEngine
array|object Optional. Available for the WiredTiger storage engine only.
Allows users to specify configuration to the storage engine on a per-collection basis when creating a collection. The value of the
storageEngine
option should take the following form:{ <storage-engine-name>: <options> }
Storage engine configurations specified when creating collections are validated and logged to the oplog during replication to support replica sets with members that use different storage engines.
typeMap
array Optional. The type map to apply to cursors, which determines how BSON documents are converted to PHP values. Defaults to the database’s type map.
This will be used for the returned command result document.
validator
array|object Optional. Allows users to specify validation rules or expressions for the collection. For more information, see Document Validation in the MongoDB manual.
The
validator
option takes an array that specifies the validation rules or expressions. You can specify the expressions using the same operators as MongoDB’s query operators with the exception of$geoNear
,$near
,$nearSphere
,$text
, and$where
.Note
- Validation occurs during updates and inserts. Existing documents do not undergo validation checks until modification.
- You cannot specify a validator for collections in the
admin
,local
, andconfig
databases. - You cannot specify a validator for
system.*
collections.
validationAction
string Optional. Determines whether to
error
on invalid documents or justwarn
about the violations but allow invalid documents to be inserted.Important
Validation of documents only applies to those documents as determined by the
validationLevel
.validationAction
Description "error"
Default. Documents must pass validation before the write occurs. Otherwise, the write operation fails. "warn"
Documents do not have to pass validation. If the document fails validation, the write operation logs the validation failure. validationLevel
string Optional. Determines how strictly MongoDB applies the validation rules to existing documents during an update.
validationLevel
Description "off"
No validation for inserts or updates. "strict"
Default. Apply validation rules to all inserts and all updates. "moderate"
Apply validation rules to inserts and to updates on existing valid documents. Do not apply rules to updates on existing invalid documents. writeConcern
MongoDB\Driver\WriteConcern Optional. Write concern to use for the operation. Defaults to the database’s write concern.
This is not supported for server versions prior to 3.4 and will result in an exception at execution time if used.
Note that not all options are available on all versions of MongoDB. Document validation, for example, was added in MongoDB 3.2; similarly, the WiredTiger storage engine is available only for MongoDB 3.0 and later. Refer to the create command reference in the MongoDB manual for compatibility considerations.
Return Values
An array or object with the result document of the create command.
Errors/Exceptions
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).
Example
The following example creates a users
collection in the test
database with document validation criteria:
The output would then resemble:
object(MongoDB\Model\BSONDocument)#11 (1) {
["storage":"ArrayObject":private]=>
array(1) {
["ok"]=>
float(1)
}
}
See Also
- create command reference in the MongoDB manual
- db.createCollection()