Mongodb中ID的序列号

Question

There is findAndModify command in Mongo DB to use auto increment numbers instead of the default ID, but I do not know how to use it for PHP driver (I am not sure if it is supported at all).

Answer 1

Ok, if you need to store incremental values i suggest you do it using some other field not the mongodb _id field mongodb used these generated id's to return some (i believe many if not all) types of queries, especially if you have a multi cluster set up then it definitely uses the _id field to locate the physical disk the data is on (i believe using a hash table or some such technology - not entirely up to date with the under the hood operations of mongo's kernel). In short, please leave this alone its designed to be an auto generated reference field.