病例情況中斷需要協助修復

Question

SQL新手，請接受我的道歉。查詢的創建，當

If HBL_CLNT_CAT._HS_EB_CODE1 = 'BF' then value = TBM_BILLGRP._HS_EB_DET1 
If HBL_CLNT_CAT._HS_EB_CODE2 = 'BF' then value = TBM_BILLGRP._HS_EB_DET2 

的_HS_EB_DET#但是超過100個字符添加一個「*」。

在協助下開發了一個查詢，但是它破壞了條件規則，因爲'then語句/操作會失敗，因爲它比條件語句（select _hs_eb_code1 from hbl_cat where hs_eb_code = 'bf'，只返回1條記錄）更大。

select 
    case when len(format) > 100 
     then left(format, 100) + '*' 
     else format 
end as format 
from 
    (select 
     case when exists (select _hs_eb_code1 
         from hbl_cat 
         where hs_eb_code = 'bf' 
         ) 
      then tbm_bllgrp._hs_eb_det1 
     end 
    ) as format 
    from tbm_bllgrp 

Answer 1

格式化代碼會幫助您找到錯誤。試試這個：

select 
    case when len(format) > 100 
     then left(format, 100) + '*' 
     else format 
    end as format 
from 
    (select 
     case when exists (select _hs_eb_code1 
         from hbl_cat 
         where hs_eb_code = 'bf' 
         ) 
      then tbm_bllgrp._hs_eb_det1 
     end as format 
    from tbm_bllgrp 
) as tmp 

Answer 2

上面的查詢在幾個地方被打破了。一個工作聲明看起來是這樣的：

SELECT CASE 
    WHEN len(x.myval) > 100 THEN 
     left(x.myval,100) + '*' 
    ELSE 
     x.myval 
    END AS format 
FROM (
    SELECT CASE 
      WHEN h.HS_EB_CODE1 = 'BF' THEN 
       t._HS_EB_DET1 
      WHEN h._HS_EB_CODE2 = 'BF' THEN 
       t._HS_EB_DET2 
      ELSE 
       'unknown option' 
      END AS myval 
     FROM HBL_CLNT_CAT AS h 
     JOIN TBM_BILLGRP AS t ON ??? -- how are the two tables connected? 
    WHERE ??? -- some condition or do you want all rows in the table? 
     ) AS x 

但是你需要先告訴我們，如何TBM_BILLGRP和HBL_CLNT_CAT可以加入，你如何選擇行。
BTW，大寫在SQL-Server中毫無意義。標識符不區分大小寫，只要它們不用雙引號" "或括號[ ]。