this is a revised question from previous one. I decided to open a new question since the scope has changed.
This is what I want to achieve.
List the last name of the author(s) of the book in an “Author” column, the last name of the author to be listed first, followed (after a comma) by that of the author to be listed second if any; and if there is a third author, put it after the second author’s name. The order of the author of a book is listed in the au_ord column (1=First Author, 2=Second Author, 3=Third Author).
Any idea how to achieve this in MYSQL output?

Those are the source table. The desired output is something like this:

All you need is a GROUP_CONCAT function.
The
GROUP BYclause groups all individual (distinct) titles, and theGROUP_CONCATon it concatenates all the authors of it. This would list all the titles and their corresponding authors. Ifau_lnameis from another table than fromtitle_idtable, then you will have to use appropriate joins. I am not sure what are the table names from your question.