[单表查询](%E5%8D%95%E8%A1%A8%E6%9F%A5%E8%AF%A2.md) [一对一查询](%E4%B8%80%E5%AF%B9%E4%B8%80%E6%9F%A5%E8%AF%A2.md) [一对多查询](%E4%B8%80%E5%AF%B9%E5%A4%9A%E6%9F%A5%E8%AF%A2.md)