如果你的mysql版本在4.1以上,可以使用如下方式SELECT t1.cardID, GROUP_CONCAT(t2.username) FROM cards as t1 LEFT JOIN cardkeep as t2 ON t1.cardID=t2.cardID GROUP BY t1.cardID;或者SELECT t1.cardID, GROUP_CONCAT(DISTINCT test_score SEPARATOR " ") FROM cards as t1 LEFT JOIN cardkeep as t2 ON t1.cardID=t2.cardID GROUP BY t1.cardID;
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