New users may make mistakes naively as they learn, but it takes an experienced developer to make the same mistakes over and over. Karwin will describe some widely used SQL techniques that should be called antipatterns, and he will offer alternative solutions. Topics include how to store a comma-separated list in a string to represent many-to-many relationships, how to create ambiguous query results with GROUP BY, how to ensure indexes are not used by the optimizer, how to give users access to run erroneous SQL themselves, and how to break five declarative and relational principles at once with EAV tables.