Porting a query with respect to SQLServer

Question

I have a query in Vectorwise DB as,

UPDATE current_load_details cld
 FROM date_dim dd
SET current_date_sk = dd.date_sk
,batchstring = date_part('YEAR', dd.dateval) || CASE 
     WHEN length(date_part('MONTH', dd.dateval)) = 1
         THEN '0' || date_part('MONTH', dd.dateval)
     ELSE date_part('MONTH', dd.dateval)
     END || CASE 
    WHEN length(date_part('DAY', dd.dateval)) = 1
        THEN '0' || date_part('DAY', dd.dateval)
     ELSE date_part('DAY', dd.dateval)
     END

     ,is_last_run_successful = 0
          WHERE cld.load_date = dd.dateval

I need to migrate it to SQLSERVER, I have tried this,

UPDATE cld.current_load_details 
 FROM dd1.date_dim 
SET current_date_sk = dd1.date_sk
,batchstring = datepart(yyyy, dd1.dateval) OR CASE 
    WHEN length(datepart(mm, dd1.dateval)) = 1
        THEN '0' OR datepart(mm, dd.dateval)
    ELSE datepart(mm, dd1.dateval)
    END OR CASE 
    WHEN length(datepart(dd, dd1.dateval)) = 1
        THEN '0' OR datepart(dd1, dd.dateval)
    ELSE datepart(dd, dd1.dateval)
    END

,is_last_run_successful = 0
     WHERE cld.load_date = dd1.dateval

It still gives error.Please help.

Answer 1

It looks like || is being uses to concatenate (rather than logical OR) the date into yyyymmdd format which in T-SQL can be done with a conversion:

 convert(varchar(8), dd1.dateval, 112)

Giving

UPDATE 
    cld.current_load_details 
SET 
    current_date_sk = dd1.date_sk,
    batchstring =  convert(varchar(8), dd1.dateval, 112),
    is_last_run_successful = 0
FROM 
    dd1.date_dim
    ??? 
WHERE cld.load_date = dd1.dateval

??? is where you presumably want to define a JOIN.