因此,基本上,我正在关注一个教程问题,该问题问我以下内容。我不太确定如何联接不包含其他FK的2个表,它们(即它们的两个FK)都位于第3个表中。我可以得到一些帮助/解释吗?我的答案SELECT Forest.Fo_name, Species.Sp_name, Species.Sp_woodtypeFROM ForestINNER JOIN SpeciesON Tree.Tr_species=Tree.Tr_forestWHERE Fo_loc='ARTIC'ORDER BY Fo_name, Sp_name“对于在编码为“ ARTIC”的区域中找到的森林,列出其中找到的森林名称和物种名称以及物种木材类型。消除任何重复,并按森林名称和物种名称对输出进行排序”种类表+--------------+------------------+------+--------------------------------+| Field | Type | Key | Glossary |+--------------+------------------+------+--------------------------------+| sp_name | C(10) | PK | Species Name || sp_woodtype | C(10) | | Wood Yielded by tree || sp_maxht | I | | Max. Height |+--------------+------------------+------+--------------------------------+森林表+--------------+------------------+------+--------------------------------+| Field | Type | Key | Glossary |+--------------+------------------+------+--------------------------------+| Fo_name | C(10) | PK | Forest Name || Fo_size | I | | Forest Area || Fo_loc | C(10) | | Geographical Area || Fo_comp | C(10) | | Forest Owner |+--------------+------------------+------+--------------------------------+C(10)&我分别代表字符(10)和Integer
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