Question

SELECT IFNULL(oea.`name`,op.name) AS "Consultation"
FROM `a` ca 
JOIN `b` oea ON ca.`consultation_id` = oea.id AND oea.status = 1
LEFT OUTER JOIN c oeal ON oea.`location_id` = oeal.id
WHERE oea.employee_profile_id IN (
                                  SELECT profile_id
                                  FROM d pp
                                  WHERE pp.status='1'
                                  UNION
                                  SELECT op.id
                                  FROM e op
                                  WHERE op.status
                                 ) AND 
      ca.status = 1

我收到此错误

Unknown column 'op.name' in 'field list'

是否有可能在范围之外使用op.name？

Answer 1

JOIN WHERE子句中的子查询，而不是使用IN谓词。这样您就可以从中选择名称。

但是你没有从子查询中选择列name。您只选择了profile_id，您必须使用profile_id选择它。类似的东西：

SELECT 
  IFNULL(oea.`name`, op.name) AS Consultation
FROM `a` ca 
JOIN `b` oea ON ca.`consultation_id` = oea.id AND oea.status = 1
INNER JOIN
(
    SELECT profile_id, name
    FROM d pp 
    WHERE pp.status='1' 
    UNION    
    SELECT op.id, name 
    FROM e op 
    WHERE op.status
) AS op ON oea.employee_profile_id = op.profile_id
LEFT OUTER JOIN c oeal ON oea.`location_id` = oeal.id
WHERE ca.status = 1;

我认为这两个表都有name列，如果其中一个没有，则必须使用null。

范围外的子查询值

1 个答案: