SQL查詢與UNION命令的問題

Question

我想做一個命令查詢，但我不知道爲什麼它不工作這是我的查詢我不知道在哪裏把訂單，我測試與每一個選擇，不工作，經過測試把它放在最後一個查詢沒有變化，你能幫我嗎？ 我想a.id

$data = null; 
         $sth = Model::connect()->prepare(" SELECT a.*, b.ciudad, d.catgoria, d.categorie, e.mark AS marka , c.fuel FROM table1 a, 
          fuel c ,ciudad b, table2 d , coches e WHERE 
          a.ciudad = b.id_vil AND a.mark = e.id AND a.fuel = c.id AND d.id = a.table3 AND a.status = 1 

          UNION 
           SELECT a.*, b.ciudad, d.catgoria, d.categorie, e.mark AS marka , c.fuel FROM table1 a, 
          fuel c ,ciudad b, table2 d , liste_vehicules_marchandises e WHERE 
          a.ciudad = b.id_vil AND a.mark = e.id AND a.fuel = c.id AND d.id = a.table3 AND a.status = 1 
          UNION 
          SELECT a.*, b.ciudad, d.catgoria, d.categorie, e.mark AS marka , c.fuel FROM table1 a, 
          fuel c ,ciudad b, table2 d , liste_vehicules_agricultures e WHERE 
          a.ciudad = b.id_vil AND a.mark = e.id AND a.fuel = c.id AND d.id = a.table3 AND a.status = 1 
          UNION 
           SELECT a.*, b.ciudad, d.catgoria, d.categorie, e.mark AS marka , c.fuel FROM table1 a, 
          fuel c ,ciudad b, table2 d , bc_vehicule e WHERE 
          a.ciudad = b.id_vil AND a.mark = e.id AND a.fuel = c.id AND d.id = a.table3 AND a.status = 1 


          "); 
                    $sth->execute(); 
                    $data = $sth->fetchAll(); 
         return $data; 

Answer 1

有訂單你可以這樣：

order by id 

，查詢中的最後一行。

此外，我會建議您使用UNION ALL而不是UNION，除非您特別要承擔刪除重複項的開銷。