摘要:
对于外连接,Oracle中可以使用“(+)”来表示,9i可以使用LEFT/RIGHT/FULL OUTER JOIN,下面将配合实例一一介绍。 1. LEFT OUTER JOIN:左外关联SELECT e.last_name, e.department_id, d.department_name FROM employees e LEFTOUTERJOIN departments d ON (e.department_id = d.department_id); 等价于SELECT e.last_name, e.department_id, d.department_name FROM em
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