I need to emulate some test data and so I need to be able insert a random number of rows, let's say from 1 to 100 rows, into MySQL table with the following schema: create table test_data ( id int ,create_date datetime ) id column must be unique b/c it is a primary key. create_date should contain the datetime when the row has been inserted. Please note that table is NOT EMPTY, i.e. it already contains a whole bunch of existing data. I want

Let's say I have a table with an integer column called ID being a primary key. It is unique and not-null, but we cannot guarantee it being sequential without gaps. I.e. we may have rows with ID = 1,2,6,7,8 and we do not have rows with ID 3,4,5 etc etc. This is why we cannot just generate a random number and get a row with that corresponding ID. Also we want all rows to have equal chance of being selected, so b/c of the gaps in ID values we ca