標識表中的重複數據

Question

如何找到具有相同的ident但不同的密鑰，即相同的 「alt_anim_ident」 和而不同 「animals_key」 動物

Answer 1

SELECT yt1.* , yt2.* /*SELECT both data, you can put * if you want too */ 
FROM yourtable yt1 
INNER JOIN yourtable yt2 /*Do self-checking*/ 
ON yt1.alt_anim_ident = yt2.alt_anim_ident /*Check those with the same alt_anim_ident*/ 
WHERE yt11.animals_key <> yt2.animals_key; /*Eliminates data which pointing to itself*/ 

Answer 2

SELECT * 
FROM thetable t         -- How to find animals 
WHERE EXISTS (         -- where (different animals) exist 
     SELECT * FROM thetable x 
     WHERE x.alt_anim_ident = t.alt_anim_ident -- that have same ident 
     AND x.animals_key <> t.animals_key  -- but different key 
     ) 
ORDER BY t.alt_anim_ident, t.animals_key 
     ;