SQL Server查詢優化日期計算

Question

我試圖找到一種更有效的方式來重新編寫我的查詢。

有什麼建議嗎？我目前也在考慮將會計月份名稱顯示爲數字本身，然後比較並返回月份名稱。

(case         --proj_end_fis_mon 
    when (MYMW.mfg_year_no = FYQM.fiscal_year_no and MYMW.mfg_month_no = 12) 
    then      
     (convert(varchar,(MYMW.mfg_year_no-1))+'-'+(case 
      when FM.fiscal_month_name like 'Jan%' then '01' 
      when FM.fiscal_month_name like 'Feb%' then '02' 
      when FM.fiscal_month_name like 'Mar%' then '03' 
      when FM.fiscal_month_name like 'Apr%' then '04' 
      when FM.fiscal_month_name like 'May' then '05' 
      when FM.fiscal_month_name like 'June' then '06' 
      when FM.fiscal_month_name like 'July' then '07' 
      when FM.fiscal_month_name like 'Aug%' then '08' 
      when FM.fiscal_month_name like 'Sep%' then '09' 
      when FM.fiscal_month_name like 'Oct%' then '10' 
      when FM.fiscal_month_name like 'Nov%' then '11' 
      when FM.fiscal_month_name like 'Dec%' then '12' 
      end)) 
    else 
    (convert(varchar,MYMW.mfg_year_no)+'-'+(case 
    when FM.fiscal_month_name like 'Jan%' then '01' 
    when FM.fiscal_month_name like 'Feb%' then '02' 
    when FM.fiscal_month_name like 'Mar%' then '03' 
    when FM.fiscal_month_name like 'Apr%' then '04' 
    when FM.fiscal_month_name like 'May' then '05' 
    when FM.fiscal_month_name like 'June' then '06' 
    when FM.fiscal_month_name like 'July' then '07' 
    when FM.fiscal_month_name like 'Aug%' then '08' 
    when FM.fiscal_month_name like 'Sep%' then '09' 
    when FM.fiscal_month_name like 'Oct%' then '10' 
    when FM.fiscal_month_name like 'Nov%' then '11' 
    when FM.fiscal_month_name like 'Dec%' then '12' 
    end)) 


    end) 

這就是我的表是這樣的：

Answer 1

假設你有會計月份號可供選擇：

Convert(VarChar(4), MYMW.mfg_year_no - 
    case when MYMW.mfg_year_no = FYQM.fiscal_year_no and MYMW.mfg_month_no = 12 then 1 
     else 0 end) + 
    '-' + Right('0' + Convert(VarChar(2), FM.fiscal_month_no), 2)