AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Mysql uuid auto generate8/27/2023 Any and all suggestions are greatly appreciated. Preliminary Conclusion / Request for Solutions Also, I get a MySQL warning warning(s): 1364 Field 'id' doesn't have a default value. CREATE TRIGGER before_insert_infoidĭirect using insert : Works, but means that the logic is not contained in the database. This version of MariaDB doesn't yet support 'multiple triggers with the same action time and event for one table'Īlso requires the columns to allow null defaults. Trigger before insert : Partially works, but only on the first column. I have found a few articles that seem to point "a direction", however I have been unable to solve this. | test | varchar(32) | YES | UNI | NULL | | | auth | varchar(32) | YES | UNI | NULL | | | note | varchar(32) | YES | UNI | NULL | | | info | varchar(32) | YES | UNI | NULL | | | Field | Type | Null | Key | Default | Extra | Required to later transform the UUID into a binary format. Strip the dashes (-) from the UUID generated by MySQL, which is Used for external lookup in other tables. See " Making UUIDs More Performant in MySQL" for a workaround.So I'm trying to create records that have:Ĥ columns that are each a different UUID generated using the MySQLįunctions: REPLACE(UUID(), '-', ''). If your UUIDs are being stored as strings they are likely to sort much slower than auto-incrementing IDs. You could accomplish this with a created_at or similar date & time column, but that isn't ideal, and many rows may share the same value.Īnother issue is if your UUID primary key is clustered (such as with MySQL's InnoDB) there is a cost to row re-ordering when inserting random UUIDs. There might be a reason why you need to know what order rows were inserted in, preferably in a way that doesn't change. Those larger indexes could have performance implications such as longer time to search and more memory needed to cache. There's a storage cost to the primary key, its index, any foreign keys, and any of their indexes. UUIDs aren't a magic bullet, there are trade-offs, and it's important to understand them.ġ6-byte UUIDs are larger than 4-byte integers or 8-byte big integers. Reasons to not use UUIDs for primary keys But if you do, and you use auto-incrementing IDs, you'll have to contend with sequence generation that doesn't produce collisions. "But primary keys shouldn't be exposed to the front-end!" But you need some kind of ID for the front-end to interact with, so what are you going to use?Īuto-incrementing IDs are difficult in a multi-master system.įirst, please don't run a multi-master system. Using a text-based random UUID V4 (universally unique identifier), also referred to as GUID (globally unique identifier) by Microsoft. On the surface, a natural choice could have been an UUID, but they are not monotonically increasing. MySQL provides the AUTOINCREMENT attribute. And if that database is supporting a RESTful web service you are likely to end up with endpoints like /users/:id that someone might be able to brute force. The auto-generated document IDs are optimized for this. The same thinking could be applied to user accounts which is even more dangerous. If you're designing a database for something like e-commerce, using an auto-incrementing ID could accidentally expose things like: how many orders exist in the system, at what rate orders are made, and so on. If that data ever needed to be migrated somewhere else, or combined with other data, you're likely to run into collision issues.Īuto-incrementing IDs expose internal information. When inserting multiple related entities to database at the same time it's easier to generate IDs ahead of time instead of needing to: start a transaction, insert the parent entity, return the last inserted row ID, then insert all the other entities.Īuto-incrementing IDs are only unique to the database and table that they came from. UUIDs can be generated before insert time. Having an auto-incrementing ID such as "1234" isn't meaningful on its own, especially in a database with dozens of tables. There's a lot of value in having an identifier refer to only one entity. UUIDs are unique across tables and databases. V10.1 (2003) introduced SYS_GUID() which is close enough Reasons to use UUIDs for primary keys
0 Comments
Read More
Leave a Reply. |