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私は奇妙な問題を抱えており、原因を特定するための助けが必要です。これまでのところ、私は症状を観察することしかできませんでした。「どうやら」起こっているのは、MySQLが最初の「LEFTJOIN」の前に改行文字があるかどうかに基づいて異なるクエリを実行しているということです。

これが私の設定です：

www.xeround.comが提供するMySQLデータベースインスタンスでクエリを実行しています。Kohanaフレームワークバージョン3.0を使用しています。LighttpdでPHP5.3.3FastCGIを実行しています。MySQLネイティブドライバーを使用してPHPをコンパイルしました。

--with-mysql = mysqlnd --with-mysqli = mysqlnd --with-pdo-mysql = mysqlnd

デフォルトのKohana3MySQLデータベースドライバーとQueryBuilderを使用しています。

それが問題のように思われるので、PHPコードをスキップしてSQLを共有します。QueryBuilderは、最終的に次のクエリを作成します。

SELECT `fieldreps`.`user_id` AS `fieldreps.user_id`, `fieldreps`.`availability_id` AS `fieldreps.availability_id`, `fieldreps`.`applicant_type` AS `fieldreps.applicant_type`, `fieldreps`.`license_number` AS `fieldreps.license_number`, `fieldreps`.`license_exp` AS `fieldreps.license_exp`, `fieldreps`.`license_state` AS `fieldreps.license_state`, `fieldreps`.`car` AS `fieldreps.car`, `fieldreps`.`authorized_worker` AS `fieldreps.authorized_worker`, `fieldreps`.`restrictions` AS `fieldreps.restrictions`, `fieldreps`.`night` AS `fieldreps.night`, `fieldreps`.`day` AS `fieldreps.day`, `fieldreps`.`longer` AS `fieldreps.longer`, `fieldreps`.`commitment` AS `fieldreps.commitment`, `fieldreps`.`travel_metro` AS `fieldreps.travel_metro`, `fieldreps`.`travel_states` AS `fieldreps.travel_states`, `fieldreps`.`big_employee` AS `fieldreps.big_employee`, `fieldreps`.`employed` AS `fieldreps.employed`, `fieldreps`.`retail` AS `fieldreps.retail`, `fieldreps`.`status` AS `fieldreps.status`, `fieldreps`.`start` AS `fieldreps.start`, `fieldreps`.`sales` AS `fieldreps.sales`, `fieldreps`.`study` AS `fieldreps.study`, `fieldreps`.`relevant` AS `fieldreps.relevant`, `fieldreps`.`experience` AS `fieldreps.experience`, `fieldreps`.`claims` AS `fieldreps.claims`, `fieldreps`.`education` AS `fieldreps.education`, `fieldreps`.`degree_details` AS `fieldreps.degree_details`, `fieldreps`.`degree_institution` AS `fieldreps.degree_institution`, `fieldreps`.`other_training` AS `fieldreps.other_training`, `fieldreps`.`jobs` AS `fieldreps.jobs`, `fieldreps`.`current_training` AS `fieldreps.current_training`, `fieldreps`.`interested` AS `fieldreps.interested`, `fieldreps`.`achievements` AS `fieldreps.achievements`, `fieldreps`.`passions` AS `fieldreps.passions`, `fieldreps`.`ambitions` AS `fieldreps.ambitions`, `fieldreps`.`max_travel_time` AS `fieldreps.max_travel_time`, `fieldreps`.`creation_time` AS `fieldreps.creation_time`, `fieldreps`.`resume` AS `fieldreps.resume`, `users`.`user_id` AS `users.user_id`, `users`.`email` AS `users.email`, `users`.`name` AS `users.name`, `users`.`password` AS `users.password`, `users`.`given_name` AS `users.given_name`, `users`.`title` AS `users.title`, `users`.`nationality` AS `users.nationality`, `availabilities`.`availability_id` AS `availabilities.availability_id`, `availabilities`.`fieldrep_id` AS `availabilities.fieldrep_id`, `availabilities`.`mon_start` AS `availabilities.mon_start`, `availabilities`.`mon_end` AS `availabilities.mon_end`, `availabilities`.`tue_start` AS `availabilities.tue_start`, `availabilities`.`tue_end` AS `availabilities.tue_end`, `availabilities`.`wed_start` AS `availabilities.wed_start`, `availabilities`.`wed_end` AS `availabilities.wed_end`, `availabilities`.`thur_start` AS `availabilities.thur_start`, `availabilities`.`thur_end` AS `availabilities.thur_end`, `availabilities`.`fri_start` AS `availabilities.fri_start`, `availabilities`.`fri_end` AS `availabilities.fri_end`, `availabilities`.`sat_start` AS `availabilities.sat_start`, `availabilities`.`sat_end` AS `availabilities.sat_end`, `availabilities`.`sun_start` AS `availabilities.sun_start`, `availabilities`.`sun_end` AS `availabilities.sun_end` FROM `fieldreps` AS `fieldreps` LEFT JOIN `users` ON (`fieldreps`.`user_id` = `users`.`user_id`) LEFT JOIN `availabilities` ON (`fieldreps`.`availability_id` = `availabilities`.`availability_id`)

これは次のような結果を返します:(私はFieldrepsテーブルから返されたフィールドのほとんどを削除して、短くして個人的なものを減らしました。）

[0] => Array
    (
        [fieldreps.user_id] => 1f01f4c2-43fd-550d-a53d-1f191786ebad
        [fieldreps.availability_id] => e31b0773-ecba-41d1-8ebb-7ac718496456
        [fieldreps.car] => Yes
        [fieldreps.authorized_worker] => Yes
        [fieldreps.restrictions] => Has Restrictions: No 
        [fieldreps.night] => Yes
        [fieldreps.day] => Yes
        [fieldreps.longer] => Yes
        [users.user_id] => 1f01f4c2-43fd-550d-a53d-1f191786ebad
        [users.email] => dsfsdfsdfsdfsdfs@sdfsdfsdfsdfsd.com
        [users.name] => Jones
        [users.password] =>
        [users.given_name] => Fred
        [users.title] => Miss
        [users.nationality] => 
        [availabilities.availability_id] => 
        [availabilities.fieldrep_id] => 
        [availabilities.mon_start] => 
        [availabilities.mon_end] => 
        [availabilities.tue_start] => 
        [availabilities.tue_end] => 
        [availabilities.wed_start] => 
        [availabilities.wed_end] => 
        [availabilities.thur_start] => 
        [availabilities.thur_end] => 
        [availabilities.fri_start] => 
        [availabilities.fri_end] => 
        [availabilities.sat_start] => 
        [availabilities.sat_end] => 
        [availabilities.sun_start] => 
        [availabilities.sun_end] => 
    )
[1] => Array
    (
        [fieldreps.user_id] => 812c3a9f-d7d8-565a-a886-1b182753dd41
        [fieldreps.availability_id] => 
        [fieldreps.car] => 1
        [fieldreps.authorized_worker] => 1
        [fieldreps.restrictions] => 
        [fieldreps.night] => 1
        [fieldreps.day] => 1
        [fieldreps.longer] => 1
        [users.user_id] => 812c3a9f-d7d8-565a-a886-1b182753dd41
        [users.email] => sdfsdfsdfsdfsdf@sdfsdfsdfsdf.com
        [users.name] => Smith
        [users.password] => 
        [users.given_name] => Jill 
        [users.title] => 
        [users.nationality] => 
        [availabilities.availability_id] => 
        [availabilities.fieldrep_id] => 
        [availabilities.mon_start] => 
        [availabilities.mon_end] => 
        [availabilities.tue_start] => 
        [availabilities.tue_end] => 
        [availabilities.wed_start] => 
        [availabilities.wed_end] => 
        [availabilities.thur_start] => 
        [availabilities.thur_end] => 
        [availabilities.fri_start] => 
        [availabilities.fri_end] => 
        [availabilities.sat_start] => 
        [availabilities.sat_end] => 
        [availabilities.sun_start] => 
        [availabilities.sun_end] =>

ただし、最初のLEFT JOINの直前に改行文字を挿入すると、次のようになります。

SELECT `fieldreps`.`user_id` AS `fieldreps.user_id`, `fieldreps`.`availability_id` AS `fieldreps.availability_id`, `fieldreps`.`applicant_type` AS `fieldreps.applicant_type`, `fieldreps`.`license_number` AS `fieldreps.license_number`, `fieldreps`.`license_exp` AS `fieldreps.license_exp`, `fieldreps`.`license_state` AS `fieldreps.license_state`, `fieldreps`.`car` AS `fieldreps.car`, `fieldreps`.`authorized_worker` AS `fieldreps.authorized_worker`, `fieldreps`.`restrictions` AS `fieldreps.restrictions`, `fieldreps`.`night` AS `fieldreps.night`, `fieldreps`.`day` AS `fieldreps.day`, `fieldreps`.`longer` AS `fieldreps.longer`, `fieldreps`.`commitment` AS `fieldreps.commitment`, `fieldreps`.`travel_metro` AS `fieldreps.travel_metro`, `fieldreps`.`travel_states` AS `fieldreps.travel_states`, `fieldreps`.`big_employee` AS `fieldreps.big_employee`, `fieldreps`.`employed` AS `fieldreps.employed`, `fieldreps`.`retail` AS `fieldreps.retail`, `fieldreps`.`status` AS `fieldreps.status`, `fieldreps`.`start` AS `fieldreps.start`, `fieldreps`.`sales` AS `fieldreps.sales`, `fieldreps`.`study` AS `fieldreps.study`, `fieldreps`.`relevant` AS `fieldreps.relevant`, `fieldreps`.`experience` AS `fieldreps.experience`, `fieldreps`.`claims` AS `fieldreps.claims`, `fieldreps`.`education` AS `fieldreps.education`, `fieldreps`.`degree_details` AS `fieldreps.degree_details`, `fieldreps`.`degree_institution` AS `fieldreps.degree_institution`, `fieldreps`.`other_training` AS `fieldreps.other_training`, `fieldreps`.`jobs` AS `fieldreps.jobs`, `fieldreps`.`current_training` AS `fieldreps.current_training`, `fieldreps`.`interested` AS `fieldreps.interested`, `fieldreps`.`achievements` AS `fieldreps.achievements`, `fieldreps`.`passions` AS `fieldreps.passions`, `fieldreps`.`ambitions` AS `fieldreps.ambitions`, `fieldreps`.`max_travel_time` AS `fieldreps.max_travel_time`, `fieldreps`.`creation_time` AS `fieldreps.creation_time`, `fieldreps`.`resume` AS `fieldreps.resume`, `users`.`user_id` AS `users.user_id`, `users`.`email` AS `users.email`, `users`.`name` AS `users.name`, `users`.`password` AS `users.password`, `users`.`given_name` AS `users.given_name`, `users`.`title` AS `users.title`, `users`.`nationality` AS `users.nationality`, `availabilities`.`availability_id` AS `availabilities.availability_id`, `availabilities`.`fieldrep_id` AS `availabilities.fieldrep_id`, `availabilities`.`mon_start` AS `availabilities.mon_start`, `availabilities`.`mon_end` AS `availabilities.mon_end`, `availabilities`.`tue_start` AS `availabilities.tue_start`, `availabilities`.`tue_end` AS `availabilities.tue_end`, `availabilities`.`wed_start` AS `availabilities.wed_start`, `availabilities`.`wed_end` AS `availabilities.wed_end`, `availabilities`.`thur_start` AS `availabilities.thur_start`, `availabilities`.`thur_end` AS `availabilities.thur_end`, `availabilities`.`fri_start` AS `availabilities.fri_start`, `availabilities`.`fri_end` AS `availabilities.fri_end`, `availabilities`.`sat_start` AS `availabilities.sat_start`, `availabilities`.`sat_end` AS `availabilities.sat_end`, `availabilities`.`sun_start` AS `availabilities.sun_start`, `availabilities`.`sun_end` AS `availabilities.sun_end` FROM `fieldreps` AS `fieldreps` 
LEFT JOIN `users` ON (`fieldreps`.`user_id` = `users`.`user_id`) LEFT JOIN `availabilities` ON (`fieldreps`.`availability_id` = `availabilities`.`availability_id`)

私は今、私が望む結果を得る：

[0] => Array
    (
        [fieldreps.user_id] => 1f01f4c2-43fd-550d-a53d-1f191786ebad
        [fieldreps.availability_id] => e31b0773-ecba-41d1-8ebb-7ac718496456
        [fieldreps.car] => Yes
        [fieldreps.authorized_worker] => Yes
        [fieldreps.restrictions] => Has Restrictions: No 
        [fieldreps.night] => Yes
        [fieldreps.day] => Yes
        [fieldreps.longer] => Yes
        [users.user_id] => 1f01f4c2-43fd-550d-a53d-1f191786ebad
        [users.email] => dsfsdfsdfsdfsdfs@sdfsdfsdfsdfsd.com
        [users.name] => Jones
        [users.password] =>
        [users.given_name] => Fred
        [users.title] => Miss
        [users.nationality] => 
        [availabilities.availability_id] => e31b0773-ecba-41d1-8ebb-7ac718496456
        [availabilities.fieldrep_id] => 1f01f4c2-43fd-550d-a53d-1f191786ebad
        [availabilities.mon_start] => 540
        [availabilities.mon_end] => 1020
        [availabilities.tue_start] => 540
        [availabilities.tue_end] => 1020
        [availabilities.wed_start] => 540
        [availabilities.wed_end] => 1020
        [availabilities.thur_start] => 540
        [availabilities.thur_end] => 1020
        [availabilities.fri_start] => 540
        [availabilities.fri_end] => 1020
        [availabilities.sat_start] => 
        [availabilities.sat_end] => 
        [availabilities.sun_start] => 
        [availabilities.sun_end] => 
    )
[1] => Array
    (
        [fieldreps.user_id] => 812c3a9f-d7d8-565a-a886-1b182753dd41
        [fieldreps.availability_id] => 
        [fieldreps.car] => 1
        [fieldreps.authorized_worker] => 1
        [fieldreps.restrictions] => 
        [fieldreps.night] => 1
        [fieldreps.day] => 1
        [fieldreps.longer] => 1
        [users.user_id] => 812c3a9f-d7d8-565a-a886-1b182753dd41
        [users.email] => sdfsdfsdfsdfsdf@sdfsdfsdfsdf.com
        [users.name] => Smith
        [users.password] => 
        [users.given_name] => Jill 
        [users.title] => 
        [users.nationality] => 
        [availabilities.availability_id] => 
        [availabilities.fieldrep_id] => 
        [availabilities.mon_start] => 
        [availabilities.mon_end] => 
        [availabilities.tue_start] => 
        [availabilities.tue_end] => 
        [availabilities.wed_start] => 
        [availabilities.wed_end] => 
        [availabilities.thur_start] => 
        [availabilities.thur_end] => 
        [availabilities.fri_start] => 
        [availabilities.fri_end] => 
        [availabilities.sat_start] => 
        [availabilities.sat_end] => 
        [availabilities.sun_start] => 
        [availabilities.sun_end] =>

UsersテーブルのLEFTJOINは、どちらのシナリオでも正常に機能することに注意してください。また、最初のLEFT JOINではなく、2番目のLEFTJOINの前に改行を追加してみました。同じ望ましくない結果。それを修正するために私が見つけることができる唯一のことは、最初のLEFTJOINの前に改行を配置することです。QueryBuilderによって作成され、MySQLに送信されるクエリは、常に長く、1行で、最小の空白文字列です...改行はありません。この問題が発生したのはこれが初めてです。最初のLEFTJOINの前に改行を入れる必要があるとは信じられません。

私の質問はこれらの点に要約されます：

  1. これはこのように起こっていると思われますか？（クエリ結果に影響する空白）
  2. 私が望む結果を得るための最善の方法は何ですか。

私はSQLの専門家ではありません。そうでなければ、おそらくこの質問をする必要はありません。私が見落としているものがあると確信しています。

ありがとうございました、

ジョナサン

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1 に答える 1

0

私の問題は私が思ったように私の目の前にありました：

インデックス

誤ってavailabilities.fieldrep_idに2つのインデックスを作成しましたが、スキーマの残りの部分のインデックスは、せいぜい見苦しいものでした。

3つの結合のうち2つにインデックスを使用していないことを示すEXPLAINを使用しました。インデックスをクリーンアップしたところ、毎回うまく機能するようになりました。

また、改行がクエリを変更する理由を理解したと思います。クエリを何度も実行すると、改行を追加するかどうかに関係なく、指定された例が切り替わることがわかります。MySQLには繰り返しクエリ用のキャッシュがあると思います。改行は、キャッシュされたバージョンを無視するようにトリガーするのに十分だったと思います。したがって、望ましい結果が得られる場合があります。

とにかく、問題は指数にありました。他のすべては単なる症状でした。

多分これは誰かが少し時間を節約するのに役立つでしょう。

于 2011-12-29T23:18:50.140 に答える