Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...

想搞定数据库，其实不难，难的是找到一本真正讲人话的入门书。👉这本《SQL必知必会（第5版）》，就是那种让人“看着看 ...