兩個SQL查詢的組合

Question

我有兩個獨立的SQL查詢，如果可能的話，我想合併成一個SQL查詢。

查詢＃1產生隨機順序表中的所有條目

查詢＃2將事後檢查結果是否可用於

在一個單一的步驟，直接在SQL我怎樣才能做到這一點？

代碼：

// start with a query for all of the photos, returned in random order 
$query = " 
SELECT DISTINCT m.mediaID 
       , m.description 
       , m.path 
       , m.alwayson 
       , m.usecollfolder 
       , m.mediatypeID 
FROM $media_table m 
WHERE m.mediatypeID = 'photos' 
ORDER BY RAND(); 
"; 
$result = mysql_query($query) or die ("$text[cannotexecutequery]: $query"); 
while($imgrow = mysql_fetch_assoc($result)) { 

    // if the picture is alwayson or we are allowing living to be displayed, 
    // we don't need to bother 
    // with any further checking 
    if ($imgrow[alwayson] || $allow_living_db) { 
    break; 

    // otherwise, let's check for living 
    } else { 

    // this query will return rows of personIDs on the photo that are living 

    $query = "  
    SELECT l.personID 
    FROM $medialinks_table l 
    JOIN $people_table p ON l.personID = p.personID 
    WHERE l.mediaID = $imgrow[mediaID] 
    AND p.living = 1 
    "; 
    $presult = mysql_query($query) or die ("$text[cannotexecutequery]: $query"); 
    $rows = mysql_num_rows($presult); 
    mysql_free_result($presult); 

    // if no rows are returned, there are no living on the photo, so let's display it 
    if ($rows == 0) { 
     break; 
    } 
} 

Answer 1

SELECT DISTINCT m.mediaID 
       , m.description 
       , m.path 
       , m.alwayson 
       , m.usecollfolder 
       , m.mediatypeID 

       , l.personID 

      FROM $media_table m 

      JOIN $medialinks_table l 
      ON l.mediaID = m.mediaID 
      JOIN $people_table p 
      ON l.personID = p.personID 
      WHERE m.mediatypeID = 'photos' 
      AND p.living = 1 

      ORDER 
      BY RAND();