Update problem

filipczako · #1 (**permalink**) December 1st, 2005, 09:25 AM

i have very simple Table in DB with 2 columns: id int PK with identity(,name-varchar(50). I have there 2 rows with some data.
Now i delete last row in DataGridView and then i add new row.
And i have id of second row=3 why ?

filipczako · #2 (**permalink**) December 1st, 2005, 09:47 AM

now i do in that way:

Code:

DataGridView1.DataSource = lpBases.dataSet.Tables[0];
            for (int i=0;i<lpBases.dataSet.Tables[0].Rows.Count;i++)
                DataGridView1[0,i].Value = i+1;

but it is not good solution...

planoie · #3 (**permalink**) December 3rd, 2005, 11:24 AM

Typically, databases that use autoincrementing columns keep track of the autoincrement counter regardless of how many rows or which IDs are still in the table. If you want to always have a sequential ID, you could use a non identity int column and manually generate the ID. However, if you delete a row, you still get a broken sequence. Also, this technique can be problematic depending on how you write your queries and how much activity there is against that table.

-Peter

filipczako · #4 (**permalink**) December 8th, 2005, 07:26 AM

Quote:

quote:Originally posted by planoie
Typically, databases that use autoincrementing columns keep track of the autoincrement counter regardless of how many rows or which IDs are still in the table. If you want to always have a sequential ID, you could use a non identity int column and manually generate the ID. However, if you delete a row, you still get a broken sequence. Also, this technique can be problematic depending on how you write your queries and how much activity there is against that table.

-Peter

but when i do many delete and add operations it is possible that i will get scope error...

planoie · #5 (**permalink**) December 10th, 2005, 11:43 PM

What scope error would you expect to get?

-Peter

filipczako · #6 (**permalink**) December 12th, 2005, 06:47 PM

Quote:

quote:Originally posted by planoie
What scope error would you expect to get?

-Peter

too big int number...

planoie · #7 (**permalink**) December 15th, 2005, 11:58 AM

Ok, I see. (That's not a scope error per se, it's a data type limitation).

Sure, if you have a SQL table with an integer field that's used as the primary key (starting at 0 going up) then you are limited to 2,147,483,648 records. If you reach that limit then you'll probably be having other problems more important to address.

-Peter

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