execute insert and select statements consecutively after a case statement

I want to execute insert and select statements once a condition is met on mysql, not sure how to do it. ##declare variables SET @fvar = 'sometxt', @svar = 'sometxtagain'; SELECT @start := 1, @finish := 10; select count(somecolumnID) as columnname, case when count(somecolumnID) = '0' then ( ##insert statement here which will automatically generate a unique id, use @fvar here ##select statement here to get the unique id (@tvar) from first insert statement ##insert statement here which will automatically generate a unique 2nd_id (@fovar), use @svar and @tvar here ##select statement here to get the unique 2nd_id from second insert statement, use @fovar here ) else 'record exist. nothing to do here' end as output from table_name where id = 'user_input';