How can I assign a set of values randomly across the column in SQL?

Question

I'm new to PostgreSQL and was trying to implement the following task. Given the column user_id in a PostgreSQL table, I wish to assign random values to the column hub_id in the same table. This hub_id should contain only values available in a list of n numbers - Eg hub_list[25,38,36,300,350].

User_id | Hub_id
1        25
2        36
3        25
4        38

How to carry out an update statement for this?

I just tried using this code but it showed only one value throughout the column, and unable to get a list of values

UPDATE <table name> SET hub_id = (select floor(random() * 10) + 1) WHERE a.hub_id = a.hub_id;

Answer 1

One method uses arrays:

UPDATE a.user_id
    SET hub_id = (array[25, 38, 36, 300, 350])[floor(1 + random()*cardinality(array[25, 38, 36, 300, 350]))];

Here is a db<>fiddle.