CTE Recursion Limitation

  • I have a set of employeids which is comma seperated and passed s parameter in a stored proc. If i take more than 100 empID it errors out saying "The maximum recursion 100 has been exhausted before statement completion". Is there a way we could set much more as a limit. the now of emplid could go even upto 7K which means i 'll have to change the CTE to use varchar(max) . Isthis comething doable. If so can someone please provide some input on this. TIA

    declare @EmpiD varchar(max)

    select @EmpiD = '100010,100104,100127,100137,100170,100216,100257,100393,100423,100438,100501,100521,100580,100629,100643,100646,100653,100659,100662,100701,100735,100831,100885,100888,100908,100921,100950,100957,100958,100960,100961,100962,100965,100971,100976,100978,100980,100983,100987,100988,100992,100997,100999,101003,101005,101006,101013,101019,101021,101025,101028,101029,101030,101035,100010,100104,100127,100137,100170,100216,100257,100393,100423,100438,100501,100521,100580,100629,100643,100646,100653,100659,100662,100701,100735,100831,100885,100888,100908,100921,100950,100957,100958,100960,100961,100962,100965,100971,100976,100978,100980,100983,100987,100988,100992'

    --,100997,100999,101003,101005,101006,101013,101019,101021,101025,101028,101029,101030,101035'

    DECLARE @Empslist TABLE( id integer, list varchar( 3000 ) );

    insert into @Empslist select 1, @EmpiD;

    -- This will be the temp table you will use to link your base tables to

    DECLARE @EmpiDs TABLE( itemNbr smallint, EmpiD int );

    -- Use a recursive Common Table Expression in order to split out the individual EmpiDs and place them into

    -- a temp table you can link to ( @EmpiDs ).

    with SplitCTE as

    (

    selectid,

    itemNbr = 1,

    startPos = 1,

    endpos = CHARINDEX( ',', list + ',') - 1

    from @Empslist

    UNION ALL

    selectprv.id,

    prv.itemNbr + 1,

    prv.endPos + 2,

    CHARINDEX( ',', curr.list + ',', prv.endPos + 2 ) - 1

    fromSplitCTE prv INNER JOIN

    @Empslist curr ON

    prv.id = curr.id AND

    CHARINDEX( ',', curr.list + ',', prv.endPos + 2 ) > 0

    )

    insert into @EmpiDs

    selectitemNbr,

    CAST( SUBSTRING( list, startPos, endPos - startPos + 1 ) as INT ) as EmpiD

    from@Empslist f INNER JOIN

    SplitCTE s ON

    f.id = s.id;

    select * into #EmpiD from @EmpiDs

    select * from #EmpiD

  • There are several other ways of splitting a delimited string, some of which are more efficient than using recursive CTEs.

    You could use a Tally table, convert to an XML string and use XQuery, or simply use a WHILE loop in a UDF.

  • Yes, there is a way to do this, but you should not do it. In fact you should not being using this approach at all: Using Recursion as a proxy for Iteration is guaranteed bad performance in every language that I know of (except Lisp).

    If you need to split a string like this, you should use a Tally/Numbers table as explained by this really smart guy in this really fine article:http://www.sqlservercentral.com/articles/T-SQL/63003/

    (ps: if you could edit your original post and put some spaces or line breaks between those commas, we could all read this much easier.)

    [font="Times New Roman"]-- RBarryYoung[/font], [font="Times New Roman"] (302)375-0451[/font] blog: MovingSQL.com, Twitter: @RBarryYoung[font="Arial Black"]
    Proactive Performance Solutions, Inc.
    [/font]
    [font="Verdana"] "Performance is our middle name."[/font]

  • Tally table method is the best way to do things like this.

    "Keep Trying"

  • Where is the stored procedure being called from?

    If it is from another stored procedure then why create the list and then seperate them?

    You can use a temp table to store the list and then query that from your called stored procedure.

    Just remember to add some checking to make sure the temp table exists.

  • The default recursion limit is 100.

    You need to add Option (MaxRecursion 32000) to the Query

    You can choose a number lower than 32000, but must be at least equal to the number of delimiters in your string.

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