在子查询

Question

拥有此COUNT子查询，但我无法使用该语法。

    SELECT products.client_id,
       clients.name AS client_name,
       cars.vin,
       cars.make,  
    cars.model
   (SELECT COUNT(*) FROM manheim_auction_listings AS listings_sub
        JOIN products ON 
          manheim_auction_listings.product_id  = products.id 
        JOIN product_purchases ON
           products.current_product_purchase_id = product_purchases.id 
       WHERE listings_sub.car_id = manheim_auction_listings.car_id AND                      
          listings_sub.id <> manheim_auction_listings.id and         
          manheim_auction_listings.product_purchase_id = 
          product_purchases.id) as previous_auction_count 
      FROM manheim_auction_listings
      JOIN cars ON 
      cars.id = manheim_auction_listings.car_id .....

（SELECT COUNT（*）不会通过JOIN传递语法我需要得到正确的计数。

Answer 1

您的内部查询中缺少GROUP BY。

WHERE listings_sub.car_id = manheim_auction_listings.car_id AND                      
      listings_sub.id <> manheim_auction_listings.id and         
      manheim_auction_listings.product_purchase_id = 
      product_purchases.id
      GROUP BY <list_of_column(s)>

此外，还有更多语法错误

在,列 必须 被cars.model分隔后，您将丢失逗号,。

 cars.model
  (SELECT COUNT(*) FROM manheim_auction_listings AS listings_sub