1

MySQL が列を見つけられないと主張するのはなぜですか? 「select句」で指定しました。

MySQL 5.1.39

エラー コード: 1054 ' WHERE句' の不明な列 ' dt '

クエリ:

-- Generate a Table for Every Day in 2008 Year
SELECT DATE_ADD('2008-01-01',
            INTERVAL (ones.num + tens.num + hundreds.num) DAY) dt
FROM
    (SELECT 0 num UNION ALL
     SELECT 1 num UNION ALL
     SELECT 2 num UNION ALL
     SELECT 3 num UNION ALL
     SELECT 4 num UNION ALL
     SELECT 5 num UNION ALL
     SELECT 6 num UNION ALL
     SELECT 7 num UNION ALL
     SELECT 8 num UNION ALL
     SELECT 9 num) ones
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 10 num UNION ALL
     SELECT 20 num UNION ALL
     SELECT 30 num UNION ALL
     SELECT 40 num UNION ALL
     SELECT 50 num UNION ALL
     SELECT 60 num UNION ALL
     SELECT 70 num UNION ALL
     SELECT 80 num UNION ALL
     SELECT 90 num) tens
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 100 num UNION ALL
     SELECT 200 num UNION ALL
     SELECT 300 num) hundreds
WHERE YEAR(dt) < 2009
ORDER BY dt;
4

3 に答える 3

3

HAVING句で列の別名を参照する必要があります。HAVING条件はWHERE、最初のクエリ実行の一部である句とは対照的に、クエリが処理された後に結果セットに対して実行されます。このためHAVING、結果セットでのみ使用可能な列エイリアスを操作できます。

-- Generate a Table for Every Day in 2008 Year
SELECT DATE_ADD('2008-01-01',
            INTERVAL (ones.num + tens.num + hundreds.num) DAY) dt
FROM
    (SELECT 0 num UNION ALL
     SELECT 1 num UNION ALL
     SELECT 2 num UNION ALL
     SELECT 3 num UNION ALL
     SELECT 4 num UNION ALL
     SELECT 5 num UNION ALL
     SELECT 6 num UNION ALL
     SELECT 7 num UNION ALL
     SELECT 8 num UNION ALL
     SELECT 9 num) ones
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 10 num UNION ALL
     SELECT 20 num UNION ALL
     SELECT 30 num UNION ALL
     SELECT 40 num UNION ALL
     SELECT 50 num UNION ALL
     SELECT 60 num UNION ALL
     SELECT 70 num UNION ALL
     SELECT 80 num UNION ALL
     SELECT 90 num) tens
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 100 num UNION ALL
     SELECT 200 num UNION ALL
     SELECT 300 num) hundreds
HAVING YEAR(dt) < 2009
ORDER BY dt;
于 2011-01-05T12:24:26.097 に答える
1

group byがない場合は、mysql固有です。次のようなことも試すことができます。

select * from (
SELECT DATE_ADD('2008-01-01',
      INTERVAL (ones.num + tens.num + hundreds.num) DAY) dt
FROM
    (SELECT 0 num UNION ALL
     SELECT 1 num UNION ALL
     SELECT 2 num UNION ALL
     SELECT 3 num UNION ALL
     SELECT 4 num UNION ALL
     SELECT 5 num UNION ALL
     SELECT 6 num UNION ALL
     SELECT 7 num UNION ALL
     SELECT 8 num UNION ALL
     SELECT 9 num) ones
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 10 num UNION ALL
     SELECT 20 num UNION ALL
     SELECT 30 num UNION ALL
     SELECT 40 num UNION ALL
     SELECT 50 num UNION ALL
     SELECT 60 num UNION ALL
     SELECT 70 num UNION ALL
     SELECT 80 num UNION ALL
     SELECT 90 num) tens
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 100 num UNION ALL
     SELECT 200 num UNION ALL
     SELECT 300 num) hundreds
dates
where year(dates.dt) < 2009 
ORDER BY dt;
于 2011-01-06T00:14:36.723 に答える
0

これらの名前付き列を使用するのは少し難しいかもしれませんが、WHERE の代わりに 'HAVING' を使用できます。

SELECT DATE_ADD('2008-01-01',
      INTERVAL (ones.num + tens.num + hundreds.num) DAY) dt
FROM
    (SELECT 0 num UNION ALL
     SELECT 1 num UNION ALL
     SELECT 2 num UNION ALL
     SELECT 3 num UNION ALL
     SELECT 4 num UNION ALL
     SELECT 5 num UNION ALL
     SELECT 6 num UNION ALL
     SELECT 7 num UNION ALL
     SELECT 8 num UNION ALL
     SELECT 9 num) ones
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 10 num UNION ALL
     SELECT 20 num UNION ALL
     SELECT 30 num UNION ALL
     SELECT 40 num UNION ALL
     SELECT 50 num UNION ALL
     SELECT 60 num UNION ALL
     SELECT 70 num UNION ALL
     SELECT 80 num UNION ALL
     SELECT 90 num) tens
CROSS JOIN
    (SELECT 0 num UNION ALL
     SELECT 100 num UNION ALL
     SELECT 200 num UNION ALL
     SELECT 300 num) hundreds
HAVING YEAR(dt) < 2009
ORDER BY dt;
于 2011-01-05T12:24:53.793 に答える