Problem: I have a large table with hundreds of test records, and would like to insert into a determined column a random user id, so the tests look more real in query results.
Solution: MySQL have a function RAND(), but it returns a random floating-point value v in the range 0 <= v < 1.0. Not what I want. The solution is to use it in conjunction with FLOOR(X), that will return the largest integer value not greater than X. So, to obtain a random integer R in the range i <= R < j, I can use the expression FLOOR(i + RAND() * (j – i)). For example, to obtain a random integer in the range the range 7 <= R < 12, I could use the following statement:
SELECT FLOOR(7 + (RAND() * 5));
And now, for my INSERT:
UPDATE `my_table` SET user_id = FLOOR(7 + RAND() * 5);
Did that worked out for you? Please let me know in the comments below.
