How to return '0' for no rows (no information) in the table

  • Hello everyone,

    I have a question. I have such a query that returns 'On Hand' result for a warehouse last year. But it returns nothing for this year because there is no inventory. I am trying to understand if there is a way to return 0 if no rows found, because I want to make a calculation SUM On Hand this year - SUM On Hand last year and therefore I need to receive 0 for no rows found.

    Does someone know how it can be done?

    DECLARE @DateKey1 DATE, @DateKey3 DATE

    SELECT @DateKey1 = CONVERT(CHAR,DATEADD(WEEK,-1,DATEADD(DAY,7-DATEPART(DW,GETDATE()), GETDATE())),112),
    @DateKey3 = CONVERT(CHAR,DATEADD(WEEK,-53,DATEADD(DAY,7-DATEPART(DW,GETDATE()), GETDATE())),112)


    SELECT IUWEDT AS TIME, IUWHS# AS DC,
    sum(IUONHD * ITCOST) AS 'OH'
    FROM table1
    WHERE CONVERT(DATETIME, CONVERT(CHAR(8), IUWEDT)) IN ( @DateKey1 , @DateKey3)
    AND IUWHS# ='22'
    AND (ITPRDC != 'AX' OR ITPRDC != ' ')
    AND ITCOST != 0
    GROUP BY IUWEDT, IUWHS#
    -- returns data for DC '22' last year
    -- doesn't return data for DC '22' this year, should return 0 and make it a calculation 'This year' - 'Last year'

    Question1

  • First of all, I have some suggestions for your existing query.

    • To obtain a DATE from a DATETIME, simply use CAST(x as DATE). Try to avoid using number-to-character-to-number conversions, because they are unnecessarily expensive.
    • != is non-ANSI syntax. It works, but most T-SQL developers use (and expect to see) <> used instead.
    • If you are going to convert something to CHAR, always explicitly state the length, or you may be in for a surprise. Try this if you don't know what the issue is
    SELECT Chars50 = REPLICATE ('x', 50)
    ,LenChars50 = LEN (CONVERT (CHAR, REPLICATE ('x', 50)));

    As far as your question is concerned, a possible solution would be to select from a CTE instead

    WITH AugmentedTable1 AS (
    SELECT IUWEDT, <other cols>
    FROM table1
    UNION ALL
    SELECT @DateKey1, <other cols with default NULL/Zero values>
    UNION ALL
    SELECT @DateKey3, <other cols with default NULL/Zero values>
    )
    SELECT <results>
    FROM AugmentedTable1

     

    If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

  • You can adjust the SUM(s).  I wasn't sure if you wanted to list only the net or all three; if you want only the net, remove the first two "OH" columns:

    SELECT IUWEDT AS TIME, IUWHS# AS DC, 
    SUM(CASE WHEN CONVERT(DATE, CONVERT(CHAR(8), IUWEDT)) IN ( @DateKey1 )
    THEN IUONHD * ITCOST ELSE 0 END) AS "OH",
    SUM(CASE WHEN CONVERT(DATE, CONVERT(CHAR(8), IUWEDT)) IN ( @DateKey3 )
    THEN IUONHD * ITCOST ELSE 0 END) AS "PRIOR_OH",
    SUM(CASE WHEN CONVERT(DATE, CONVERT(CHAR(8), IUWEDT)) IN ( @DateKey1 )
    THEN IUONHD * ITCOST ELSE 0 END) -
    SUM(CASE WHEN CONVERT(DATE, CONVERT(CHAR(8), IUWEDT)) IN ( @DateKey3 )
    THEN IUONHD * ITCOST ELSE 0 END) AS "NET_OH"
    FROM table1
    WHERE CONVERT(DATE, CONVERT(CHAR(8), IUWEDT)) IN ( @DateKey1 , @DateKey3)
    AND IUWHS# = '22'
    AND (ITPRDC <> 'AX' OR ITPRDC <> ' ')
    AND ITCOST <> 0
    GROUP BY IUWEDT, IUWHS#

    SQL DBA,SQL Server MVP(07, 08, 09) A socialist is someone who will give you the shirt off *someone else's* back.

  • This is not an aswer to your question, but...

    Your criteria AND (ITPRDC != 'AX' OR ITPRDC != ' ') looks wrong to me. And it's not your use of the non-ASCII != instead of the normal <> that makes me say so.

    I just find it odd to use OR in conjunction with two != criterias on the same column, i.e. select everything, except 'AX' or select everything, except blanks. One of those criterias will always be true, which makes the line irrelevant.

    Maybe you meant AND NOT (ITPRDC = 'AX' OR ITPRDC = ' '), which would make more sense?

     

    • This reply was modified 11 months, 2 weeks ago by  kaj. Reason: added "on the same column" to avoid ambiguity
  • It seems you could use COUNT in the SELECT list.  COUNT always returns an INT even if the FROM clause returns no rows

    declare
    @max_num int=0,
    @row_count int=0;

    select @max_num=max(num),
    @row_count=count(*)
    from (values (1),(2),(3)) v(num)
    where 1=0;

    select @max_num, @row_count;

    Aus dem Paradies, das Cantor uns geschaffen, soll uns niemand vertreiben können

  • kaj wrote:

    This is not an aswer to your question, but...

    Your criteria AND (ITPRDC != 'AX' OR ITPRDC != ' ') looks wrong to me. And it's not your use of the non-ASCII != instead of the normal <> that makes me say so.

    I just find it odd to use OR in conjunction with two != criterias on the same column, i.e. select everything, except 'AX' or select everything, except blanks. One of those criterias will always be true, which makes the line irrelevant.

    Maybe you meant AND NOT (ITPRDC = 'AX' OR ITPRDC = ' '), which would make more sense?

    I prefer AND ITPRDC NOT IN ('AX', ''), because it reinforces that the values are from a single field.

    Also, one of those criteria will NOT always be true if ITPRDC allows NULL values.  SQL uses three-value logic, and your statement only takes two into account.

    Drew

    J. Drew Allen
    Business Intelligence Analyst
    Philadelphia, PA

  • Thanks everyone for your help. It worked for me.

    Scott, your idea helped me a lot. Thanks!!

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