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    <p>No, you can't join to a different table per row in <code>table1</code>, not even with dynamic SQL as @Cade Roux suggests. </p> <p>You could join to the <code>hotdog</code> table for rows where food is 'hotdog' and join to other tables for other specific values of food.</p> <pre><code>SELECT * FROM table1 JOIN hotdog ON id = foodid WHERE food = 'hotdog' UNION SELECT * FROM table1 JOIN apples ON id = foodid WHERE food = 'apples' UNION SELECT * FROM table1 JOIN soups ON id = foodid WHERE food = 'soup' UNION ... </code></pre> <p>This requires that you know all the distinct values of food, and that all the respective food tables have compatible columns so you can UNION them together.</p> <p>What you're doing is called <em>polymorphic associations</em>. That is, the foreign key in <code>table1</code> references rows in multiple "parent" tables, depending on the value in another column of <code>table1</code>. This is a common design mistake of relational database programmers.</p> <p>For alternative solutions, see my answers to:</p> <ul> <li><a href="https://stackoverflow.com/questions/441001/possible-to-do-a-mysql-foreign-key-to-one-of-two-possible-tables/441111#441111">Possible to do a MySQL foreign key to one of two possible tables?</a></li> <li><a href="https://stackoverflow.com/questions/922184/why-can-you-not-have-a-foreign-key-in-a-polymorphic-association/922341#922341">Why can you not have a foreign key in a polymorphic association?</a></li> </ul> <p>I also cover solutions for polymorphic associations in my presentation <a href="http://www.slideshare.net/billkarwin/practical-object-oriented-models-in-sql" rel="nofollow noreferrer">Practical Object Oriented Models In SQL</a>, and in my book <a href="http://pragprog.com/book/bksqla/sql-antipatterns" rel="nofollow noreferrer">SQL Antipatterns: Avoiding the Pitfalls of Database Programming</a>.</p>
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