涉及3个表的sql查询

我有3张桌子，就像：-

    Table_1               Table_2                    Table_3
------------------------  --------------------  --------------------
id  bk_title  strm_id     bk_no   bk_isbn            s_id    strm_name
-----------------------  ---------------------  -----------------------
1   A_Book    3           1       ISBN0001           3       Science
2   B_Book    4           1       ISBN0002           4       History
                          2       ISBN0003

我想把记录作为

BK_Title    Num_Copies  Stream
---------------------------------------
A_Book      2       Science
B_Book      1       History

我该怎么做。请给出建议。

试试这个：

SELECT BK_Title, COUNT(Table_2.bk_isbn) AS Num_Copies, Table_2.strm_name AS Stream
FROM Table_1
JOIN Table_2 on (Table_1.id = Table_2.bk_no)
JOIN Table_3 on (Table_1.strm_id = s_id)
GROUP BY BK_Title, strm_name
ORDER BY BK_Title

---

这是一个包含两个联接和一个group by的基本查询。感谢领先和向下投票。但是，选择a.BK_TITLE，将（*）计数为num_副本，c.strm_name from table_1 a JOIN table_2 b On a.id=b.BK_no JOIN table_3 c On a.strm_id=c.strm_id group by a.BK_TITLE不编译。我不投反对票。谢谢@alxdroidev的回答。