发布于 2015-09-14 14:59:13 | 122 次阅读 | 评论: 0 | 来源: 网络整理
The $pull operator removes all instances of a value from an existing array. Consider the following example:
db.collection.update( { field: value }, { $pull: { field: value1 } } );
$pull removes the value value1 from the array in field, in the document that matches the query statement { field: value } in collection. If value1 existed multiple times in the field array, $pull would remove all instances of value1 in this array.