Mybatis框架写Dao.xml

Question

ABC三个表，A中a_id是B中的外键，B中的b_id是C中的外键，提取ABC表中某些数据时，Testdao.xml如何写，求指教

Answer 1

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

Answer 2

select * from A  left join B on A.a_id=B.a_id left join C on B.b_id=C.b_id;