“无效列名”，按子查询的别名排序

您不能以这种方式按别名排序。

第一种选择是重复代码。注意：仅仅因为重复代码，SQL引擎就不会天真地再次执行它，而是重用了结果。

ORDER BY  CASE WHEN @orderby = 'default' THEN l.aanmaakdatum END DESC,  CASE WHEN @orderby = 'type' THEN l.type END ASC,   CASE WHEN @orderby = 'naam' THEN l.naam END ASC,  CASE WHEN @orderby = 'reacties' THEN (SELECt          COUNT(lead_regel_id)        FROM          Lead_regel As lr        WHERe         Lr.lead_id = l.lead_id And          Lr.status <> 100      ) END DESC

或全部使用子查询…

  SELECt    *  FROM  (    yourQuery  )    AS sub_query  ORDER BY      CASE WHEN @orderby = 'default'  THEN aanmaakdatum  END DESC,      CASE WHEN @orderby = 'type'     THEN type          END ASC,       CASE WHEN @orderby = 'naam'     THEN naam          END ASC,      CASE WHEN @orderby = 'reacties' THEN aantal_regels END DESC