Cursor does duplicate records

antonopn

Hello there,

this is my problem. I have a table in sql server. lets say it table_read.
I use a cursor like this.

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 DECLARE CUR CURSOR FOR SELECT * FROM TABLE_READ

OPEN CUR 

WHILE @@FETCH_STATUS=0

BEGIN

FETCH NEXT FROM CUR INTO 

@local_var1

@local_var2

...
 
INSERT INTO TABLE_WRITE VALUES (@local_var1, @local_var2...)

END

CLOSE CUR

DEALLOCATE CUR

GO

But my problem is that the last row of table_read is inserted twice in table_write!

Any solutions? Should I fix the cursor or try to remove duplicate records from table_write?

Thank you!

Delerna

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DECLARE CUR CURSOR FOR SELECT * FROM TABLE_READ

OPEN CUR 

FETCH NEXT FROM CUR INTO 

@local_var1

@local_var2
 
WHILE @@FETCH_STATUS=0

BEGIN

   INSERT INTO TABLE_WRITE VALUES (@local_var1, @local_var2...)

   FETCH NEXT FROM CUR INTO 

   @local_var1

   @local_var2

END

CLOSE CUR

DEALLOCATE CUR

GO

May I ask, why are you using a cursor for this?

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INSERT INTO TABLE_WRITE 

SELECT * FROM TABLE_READ

would run far faster than the cursor
cursors are recommended as a last resort only because they are slow and inefficient

antonopn

Thanks for your answer!

Lets suppose I need cursor! My problem is not why should I use cursor but why this "mistake" occurs!

Delerna

my apologies
I gave you the answer

antonopn

MY APOLOGIES not yours :)
Thanks for the answer one more time!!!

It works fine!!!

Cursor does duplicate records

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re: Cursor does duplicate records

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