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Stored Procedure with Cursor Replace then Update

Posted on 2004-10-05
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Last Modified: 2012-06-27
I have not done any work with cursor's before in a stored procedure, I've researched it, but I can seem to get my head around it

I have a variable @message char(1000)

I have table contacts

I need to query table contacts where userid = @userid
With the results, I need to add records to another table cque
With that though, the varaiable @message may have text in it that I need to replace before adding it to the cque table

So I dont know how this would all work... but logically, I see it

---------------------------------------------------------------------------------
ALTER      PROCEDURE [dbo].[sp_broadcast]
      @userid int,
                @message char(1000)

-- Declare cursor and query contacts table
DECLARE c CURSOR

For Select * from contacts where userid = @userid

open c
WHILE (@@FETCH_STATUS=0) BEGIN

/*
Here's where I get confused
I need to get fields from the cursor and do a replace such as
REPLACE(@message,'-fname-',cursorfnamevalue)
REPLACE(@message,'-lname-',cursorlnamevalue)
REPLACE(@message,'-phone-',cursorphonevalue)
*/
END

close c

deallocate c
-------------------------------------------------------------

I think I'm halfway there... I just dont know how to put it all together... I think what I dont know how to do is how to get the values out of the cursor... not sure

Help!
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Comment
Question by:Michael Krumpe
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8 Comments
 
LVL 2

Expert Comment

by:vidnan123
ID: 12234799
I think it is pretty simple....

You could do the following...

---------------------------------------------------------------------------------
ALTER      PROCEDURE [dbo].[sp_broadcast]
     @userid int,
                @message char(1000)

-- Declare cursor and query contacts table
DECLARE c CURSOR FOR
Select fname,lname,phone from contacts where userid = @userid

open c
FETCH NEXT FROM c INTO @fname,@lname, @phone

WHILE (@@FETCH_STATUS=0) BEGIN

       REPLACE(@message,'-fname-',@fname)
       REPLACE(@message,'-lname-',@lname)
       REPLACE(@message,'-phone-',@phone)

FETCH NEXT FROM c INTO @fname,@lname, @phone
END

close c
deallocate c
-------------------------------------------------------------

Let me know if u have further questions...

Here I presume the table contacts has columns like fname,lname,phone...
0
 
LVL 34

Expert Comment

by:arbert
ID: 12234815
Why are you using a cursor?

insert into yourothertable (value1, value2)
select replace(@message,'-fname-', fname),
replace(@message,'-lname-', lname),
replace(@message,'-phone-', phonevalue)
from contacts


FNAME, LNAME, and Phonevalue would be the actual column names from your contacts table...

Brett
0
 
LVL 12

Expert Comment

by:ill
ID: 12234839
--  you must specify all variables from select, when opening cursor. so choose only those, you need and with correct datatype.
ALTER      PROCEDURE [dbo].[sp_broadcast]
     @userid int,
                @message char(1000)
declare @curVariableForCol1 int,@curVariableForCol2 varchar(20),@curVariableForCol3 int
DECLARE c CURSOR
For Select col1, col2,col3, ... from contacts where userid = @userid
open c
fetch next from c into @curVariableForCol1, @curVariableForCol2, @curVariableForCol3 /* from now col1,col2 and col3 are stored in variables declared above */
WHILE (@@FETCH_STATUS=0) BEGIN
/*

REPLACE(@message,'-fname-',cursorfnamevalue)
REPLACE(@message,'-lname-',cursorlnamevalue)
REPLACE(@message,'-phone-',cursorphonevalue)
*/
fetch next from c into @curVariableForCol1, @curVariableForCol2, @curVariableForCol3

END
close c
deallocate c


--rem: but do you really need a cursor?  something like this query is not working?
insert into cque
select clumn1, column2,..., REPLACE(@message,'-fname-',cursorfnamevalue)
from contacts where userid = @userid

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LVL 34

Expert Comment

by:arbert
ID: 12234845
actually, you would have one more value so the columns match:

insert into yourothertable (value1, value2,value3)

value1, value2, value3 are the columns in the table you want to insert into.

Maybe if you expand a little more on what you're trying to do.  I don't see, based on your post, why you need a cursor.  Cursors should be avoided unless needed...
0
 
LVL 5

Expert Comment

by:hkamal
ID: 12235354
Agree with arbert. I don't think you need a cursor. A combination of CASE / REPLACE statements should do it
Cursors are slower, more complicated, and usually, avoidable
0
 
LVL 143

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 2000 total points
ID: 12235682
if message contains all the values:

ALTER      PROCEDURE [dbo].[sp_broadcast]
     @userid int,
                @message char(1000)

insert into yourothertable (column)
select replace(replace(replace(@message,'-fname-', fname),'-lname-', lname),'-phone-', phonevalue)
from contacts
where userid = @userid

GO

in the cursor sample, it would be similar, I think you simply miss the assignment:

ALTER      PROCEDURE [dbo].[sp_broadcast]
     @userid int,
                @message char(1000)

-- Declare cursor and query contacts table
DECLARE c CURSOR FOR
Select fname,lname,phone from contacts where userid = @userid

open c
FETCH NEXT FROM c INTO @fname,@lname, @phone

WHILE (@@FETCH_STATUS=0) BEGIN

       SET @message= REPLACE(@message,'-fname-',@fname)
       SET @message= REPLACE(@message,'-lname-',@lname)
       SET @message= REPLACE(@message,'-phone-',@phone)
 
      insert into yourtable ( yourcolumn ) values (@message )

FETCH NEXT FROM c INTO @fname,@lname, @phone
END

close c
deallocate c


Note that for this kind of work, the CURSOR will be MUCH SLOWER than the single-insert version...

CHeers
0
 
LVL 4

Author Comment

by:Michael Krumpe
ID: 12237536
So much great feedback. I only chose a cursor as I didnt know that I could do a replace inside a select, inside an insert statement. I will try that.
0
 
LVL 34

Expert Comment

by:arbert
ID: 12237818
"So much great feedback. I only chose a cursor as I didnt know that I could do a replace inside a select, inside an insert statement. I will try that."

Definately--only think about using a cursor as a last resort :)
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