sql server - Why is my T-SQL cursor executing twice? -


sql-server code:

declare @offers varchar(100) declare @offers_seq varchar(100)  declare result cursor     select top 1 offers,offers_seq [rezjqwb01]..activebooking_offersdetails_seq open result while @@fetch_status=0 begin     fetch next result @offers, @offers_seq     declare @value varchar(100) = @offers     while len(@value) >= 1     begin         set @value = substring(@value,charindex(';',@value)+1,len(@value))         print @value     end end close result deallocate result

what i'm trying accomplish here split set of delimited values present in 1 cell , creating cursor complete column. first time run code gives below output:

2;6;7;8;9;12;13;14;17;19;21; 6;7;8;9;12;13;14;17;19;21; 7;8;9;12;13;14;17;19;21; 8;9;12;13;14;17;19;21; 9;12;13;14;17;19;21; 12;13;14;17;19;21; 13;14;17;19;21; 14;17;19;21; 17;19;21; 19;21; 21;  2;6;7;8;9;12;13;14;17;19;21; 6;7;8;9;12;13;14;17;19;21; 7;8;9;12;13;14;17;19;21; 8;9;12;13;14;17;19;21; 9;12;13;14;17;19;21; 12;13;14;17;19;21; 13;14;17;19;21; 14;17;19;21; 17;19;21; 19;21; 21;

ideally should print once i'm not sure why loop runs twice. second time run this, gives output : 'command(s) completed successfully'.

kindly help. thanks.

the reason running twice aren't doing fetch until after you've checked @@fetch_status.

the steps this:

  1. check @@fetch_status, zero, since nothing has been fetched.
  2. fetch result
  3. run substring code
  4. check @@fetch_status again, still zero, because record fetched in previous step
  5. fetch result, fails cursor still pointing @ same row before
  6. run substring code again, same result
  7. check @@fetch_status again, returns -1 because previous fetch failed.

for same reason 2 results running once, nothing second time, because @@fetch_status -1 previous execution. fix both issues, need fetch before checking status. you'll see 1 of following methods employed (psuedocode left exercise implement). typically use first option, find second easier read:

-- (declare , open cursor) while 1=1 begin     fetch next cursor     if @@fetch_status <> 0 break;     -- (do stuff) end

or

-- (declare , open cursor) fetch next cursor while @@fetch_status = 0 begin     -- (do stuff)     fetch next cursor end

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