SELECT AVG(A) FROM (SELECT ZQQ_WD_JL_J A FROM YX_LY_SSHLYXRZ_ZYCS WHERE NVL(ZQQ_WD_JL_J,0)!=0 UNION ALL SELECT ZQQ_WD_JL_Y A FROM YX_LY_SSHLYXRZ_ZYCS WHERE NVL(ZQQ_WD_JL_Y,0)!=0);报错ORA-00904: invalid column name请问这SQL怎么定义列的别名
调试欢乐多
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1SQL> select avg(a) from (select num a from aaa union all select num a from aaa); AVG(A)
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1无什么问题,细心检查程序那里出错