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分享程序员开发的那些事...
且构网 - 分享程序员编程开发的那些事

现有表上的派生/计算列

更新时间:2023-02-03 17:32:49

SELECT    l.*, 
          q.summary AS SummaryPreviousYear
FROM      lists l
LEFT JOIN 
     (
          SELECT    Date, 
                    Summary
          FROM      lists 
          WHERE     MONTH(Date) = 12
     ) AS q  
          ON YEAR(l.Date) = YEAR(q.Date) + 1