MySQLの選択条件（その2）

Question

私の元の質問はここにある：今

SELECT id 
FROM leads t JOIN 
     (SELECT "OKQ" as status, 86400 as diff UNION ALL 
     SELECT "PI" as status, 3600 as diff UNION ALL 
     SELECT "CBK" as status, 60 as diff UNION ALL 
     SELECT "NRP" as status, 3600 as diff UNION ALL 
     SELECT "NEW" as status, 1 as diff 
     ) s 
ON t.status = s.status 
WHERE t.time > date_sub(now(), interval s.diff second) 
ORDER BY RAND() LIMIT 1 

：mySQL conditional select?

が今私の本当の状況にゴードン・リノフによって提案された第二のコードを適応した後、クエリは次のようになりsouldこのクエリはエラーをスローします：

ErreurColumn 'status' in field list is ambiguous 

Answer 1

あなたの質問は、このエラーを生成できません。すべての列名が修飾されている場合、エラーは発生しません（修飾されていない唯一の名前はidです）。

SELECTには、idより多くの列が含まれている可能性があります。あなたはどちらかSELECT t.*べきか、別の方法は、USING句を使用することです：

SELECT . . . 
FROM leads t JOIN 
    (SELECT 'OKQ' as status, 86400 as diff UNION ALL 
     SELECT 'PI' as status, 3600 as diff UNION ALL 
     SELECT 'CBK' as status, 60 as diff UNION ALL 
     SELECT 'NRP' as status, 3600 as diff UNION ALL 
     SELECT 'NEW' as status, 1 as diff 
    ) s 
    USING (status) 
WHERE t.time > date_sub(now(), interval s.diff second) 
ORDER BY RAND() 
LIMIT 1;