命名了一系列

Question

我想通了如何在一個特定的數據庫表顯示重複值的列表子查詢（PHP/MySQL的）的...

$stm = $pdo->prepare("SELECT URL, COUNT(*) tot 
FROM people 
GROUP BY URL 
HAVING tot > 1"); 
$stm->execute(array(
    'Total'=>$Total 
)); 

while ($row = $stm->fetch()) 
{ 
$URL_Dupe = $row['URL']; 
$tot = $row['tot']; 
$Dupe2[] = ''.$URL_Dupe.''.$tot.''; 
} 

我希望做同樣的事情用系列與UNION ALL子句鏈接在一起的表...

$stm = $pdo->prepare("SELECT 'GZ' AS GSiteID, NULL as Site, 'Life' AS GSection, GZL.Taxon AS URL 
FROM gz_life GZL WHERE GZL.Taxon = :MyURL 
UNION ALL 
SELECT 'All' AS GSiteID, NULL as Site, 'World' AS GSection, GG.Name AS URL FROM gw_geog GG WHERE GG.Name = :MyURL 
UNION ALL 
SELECT 'PX' AS GSiteID, Site, 'People' AS GSection, Ppl.URL FROM people Ppl WHERE Ppl.URL = :MyURL"); 
$stm->execute(array(
'MyURL'=>$MyURL 
)); 

換句話說，我想在兩個或兩個以上追查出現不止一次在單個表或一次（或更多）的任何單詞不同的表格。

但我想我必須首先爲所有這些表創建一個名稱（例如「Todo」），然後對該名稱執行操作，對吧？我怎麼做？我有一個類似的表，只是以「AS X」結尾。但是我不能在沒有出現錯誤的情況下在查詢上做到這一點。

Answer 1

可以使union all查詢子查詢，然後彙總他們像：

select url, count(*) 
from ((SELECT 'GZ' AS GSiteID, NULL as Site, 'Life' AS GSection, GZL.Taxon AS URL 
     FROM gz_life GZL WHERE GZL.Taxon = :MyURL 
    ) UNION ALL 
     (SELECT 'All' AS GSiteID, NULL as Site, 'World' AS GSection, GG.Name AS URL 
     FROM gw_geog GG WHERE GG.Name = :MyURL 
    ) UNION ALL 
     (SELECT 'PX' AS GSiteID, Site, 'People' AS GSection, Ppl.URL 
     FROM people Ppl WHERE Ppl.URL = :MyURL 
    ) 
    ) t 
group by url; 

如果你真的要滿足的條件：「我想追查出現不止一次在一個表中的任何字或者一次（或多次）在兩個或更多不同的表中「。這相當於數至少爲2，所以添加having條款：

select url, count(*) 
from ((SELECT 'GZ' AS GSiteID, NULL as Site, 'Life' AS GSection, GZL.Taxon AS URL 
     FROM gz_life GZL WHERE GZL.Taxon = :MyURL 
    ) UNION ALL 
     (SELECT 'All' AS GSiteID, NULL as Site, 'World' AS GSection, GG.Name AS URL 
     FROM gw_geog GG WHERE GG.Name = :MyURL 
    ) UNION ALL 
     (SELECT 'PX' AS GSiteID, Site, 'People' AS GSection, Ppl.URL 
     FROM people Ppl WHERE Ppl.URL = :MyURL 
    ) 
    ) t 
group by url 
having count(*) > 1;