php - How is this encoding string generated?

Question

"systemid":"CA1A351F-F59A-0206-E043-0A8229050206"
像这个码有点像条形码，如何保证唯一性

Answer 1

This is UUID. The issues you are concerned about are here: Universal Unique Identification Code, algorithm reference java.util.UUID.java, standard RFC4122 for UUID

The total number of UUIDs has reached 2^128 (3.4×10^38). The possibility of randomly generating two identical UUIDs is very small, but there is still the possibility of repetition, so the generation algorithm usually adds non-random parameters. such as time, to further reduce the likelihood of duplication.

Answer 2

uuid: https://www.uuidgenerator.net/
guid: https://guidgenerator.com/onl...

Examples of available libraries: https://packagist.org/package...

Answer 3

Use uuid