SQL Server查询优化日期计算

Question

我试图找到一种更有效的方式来重新编写我的查询。

有什么建议吗？我目前也在考虑将会计月份名称显示为数字本身，然后比较并返回月份名称。

(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) 

这就是我的表是这样的：

Answer 1

假设你有会计月份号可供选择：

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)