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r.mcreal
Asked:2020-02-22 22:33:16 +0000 UTC2020-02-22 22:33:16 +0000 UTC

按价值对产品进行排序

  • 772

你好！有一个显示所有产品的查询：

SELECT p.product_id, 
 (SELECT AVG(rating) AS total 
  FROM oc_review r1 
  WHERE r1.product_id = p.product_id AND r1.status = '1' 
  GROUP BY r1.product_id) AS rating, 
 (SELECT price 
  FROM oc_product_discount pd2 
  WHERE pd2.product_id = p.product_id 
    AND pd2.customer_group_id = '1' 
    AND pd2.quantity = '1' 
    AND ((pd2.date_start = '0000-00-00' OR pd2.date_start < NOW()) 
    AND (pd2.date_end = '0000-00-00' OR pd2.date_end > NOW())) 
  ORDER BY pd2.priority ASC, pd2.price ASC LIMIT 1) AS discount, 
 (SELECT price 
  FROM oc_product_special ps 
  WHERE ps.product_id = p.product_id 
    AND ps.customer_group_id = '1' 
    AND ((ps.date_start = '0000-00-00' OR ps.date_start < NOW()) 
    AND (ps.date_end = '0000-00-00' OR ps.date_end > NOW())) 
  ORDER BY ps.priority ASC, ps.price ASC LIMIT 1) AS special 
FROM oc_product_to_category p2c 
LEFT JOIN oc_product p ON (p2c.product_id = p.product_id) 
LEFT JOIN oc_product_description pd ON (p.product_id = pd.product_id) 
LEFT JOIN oc_product_to_store p2s ON (p.product_id = p2s.product_id) 
  WHERE pd.language_id = '1' 
    AND p.status = '1' 
    AND p.date_available <= NOW() 
    AND p2s.store_id = '0' 
    AND p2c.category_id = '76' 
GROUP BY p.product_id 
ORDER BY rating ASC, LCASE(pd.name) ASC 
LIMIT 0,15

我需要先显示所有具有 的产品，position=1然后再显示所有其他产品。我试图在最后添加ORDER BY position='1' DESC，给出了一个错误。PS 请告诉我，我在哪里犯了错误（在 mysql 中，不幸的是，我理解马马虎虎）

mysql

1 个回答

  1. Best Answer
    SELECT p.product_id, 
 (SELECT AVG(rating) AS total 
  FROM oc_review r1 
  WHERE r1.product_id = p.product_id AND r1.status = '1' 
  GROUP BY r1.product_id) AS rating, 
 (SELECT price 
  FROM oc_product_discount pd2 
  WHERE pd2.product_id = p.product_id 
    AND pd2.customer_group_id = '1' 
    AND pd2.quantity = '1' 
    AND ((pd2.date_start = '0000-00-00' OR pd2.date_start < NOW()) 
    AND (pd2.date_end = '0000-00-00' OR pd2.date_end > NOW())) 
  ORDER BY pd2.priority ASC, pd2.price ASC LIMIT 1) AS discount, 
 (SELECT price 
  FROM oc_product_special ps 
  WHERE ps.product_id = p.product_id 
    AND ps.customer_group_id = '1' 
    AND ((ps.date_start = '0000-00-00' OR ps.date_start < NOW()) 
    AND (ps.date_end = '0000-00-00' OR ps.date_end > NOW())) 
  ORDER BY ps.priority ASC, ps.price ASC LIMIT 1) AS special 
FROM oc_product_to_category p2c 
LEFT JOIN oc_product p ON (p2c.product_id = p.product_id) 
LEFT JOIN oc_product_description pd ON (p.product_id = pd.product_id) 
LEFT JOIN oc_product_to_store p2s ON (p.product_id = p2s.product_id) 
  WHERE pd.language_id = '1' 
    AND p.status = '1' 
    AND p.date_available <= NOW() 
    AND p2s.store_id = '0' 
    AND p2c.category_id = '76' 
GROUP BY p.product_id 
ORDER BY rating ASC, LCASE(pd.name) ASC, position='1' DESC 
LIMIT 0,15

    首先按评分字段排序。然后，如果 rating 字段中有单行，则按 pd.name 字段排序。只有这样，如果两个字段中同时存在相同的行，则按值 position='1' 对其进行排序

    如果您对 MARTIN GRUBER 的“理解 SQL”一书感兴趣，您将找到所需的一切

    • 1

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