MongoCollection::deleteIndex
(PECL mongo >=0.9.0)
MongoCollection::deleteIndex — Deletes an index from this collection
说明
$keys ) :
array
This method is identical to:
<?php
public function deleteIndexes($keys) {
$indexName = $this->toIndexString($keys);
return $this->db->command(array(
"deleteIndexes" => $this->getName(),
"index" => $indexName,
));
}
?>
Each index is given a unique name when it is created. This is often generated by the driver based on the index key(s) and order/type, but custom names may also be specified with MongoCollection::createIndex()'s "name" option).
Unfortunately, MongoCollection::deleteIndex() cannot delete custom-named indexes due to a backwards compatibility issue. When a string argument is provided, it is assumed to be the single field name in an ascending index (e.g. the name "x_1" would be used for the argument "x"). If an array or object is provided, an index name is generated just as if that argument was passed to MongoCollection::createIndex().
In order to delete a custom-named index with the PHP driver, the deleteIndexes database command must be used. For instance, an index named "myIndex" could be deleted with the PHP driver by running:
<?php
$db->command(array(
"deleteIndexes" => $collection->getName(),
"index" => "myIndex",
));
?>
To determine the name of an index with the PHP driver, you can query the system.indexes collection of a database and look for the "name" field of each result. The "ns" field will indicate the collection to which each index belongs.
参数
-
keys -
An array specifying the index's fields as its keys. For each field, the value is either the index direction or » index type. If specifying direction, specify 1 for ascending or -1 for descending.
If a string is provided, it is assumed to be the single field name in an ascending index.
返回值
Returns the database response.
范例
Example #1 MongoCollection::deleteIndex() example
This example passes the function string and array parameters.
<?php
$m = new MongoClient();
$c = $m->example->indices;
// create and remove a simple index
$c->createIndex(array("i"=>1));
$c->deleteIndex("i");
// create and remove a multi-key index
$c->ensureIndex(array("j" => 1, "k" => 1));
$c->deleteIndex(array("j" => 1, "k" => 1));
?>
参见
- MongoCollection::createIndex() - Creates an index on the specified field(s) if it does not already exist
- MongoCollection::deleteIndexes() - 删除集合的所有索引
- MongoCollection::toIndexString() - Converts keys specifying an index to its identifying string
- The MongoDB » index and » index type documentation.
