Couple of Recos: O'Reilly's "Learning SQL" is probably the best intro to relational databases I've seen. While old, Reissig's "Secrets of the Database Ninja" is fantastic for understanding what the heck's going in that weird franken-language. Re the comments on books vs courses and videos.... buying a good library is IMHO a much better investment. You learn where things are in your shelf and can find further info in seconds. This becomes even more valuable as searching for technical stuff gets worse every year. Also, good books teach you what you don't know you need to know, rather than what everyone knows they are looking for.
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