Setting up a primary Key on C# Window Form App

Christopher Hankwembo

8y1.2k

Hi Experts

I would like to set a primary on my form in C# because at the moment whenever I try to save data an error pops up as follows:

(1) StaffID is not Nullable , please check again?????

is there a way to sort out this????????

The data is properly binded to the data tables in SQL server 2016 using the wizard and is saved by using the built in Navigator binding source with a small modification below:

this.Validate();

this.customersBindingSource.EndEdit();

this.ordersBindingSource.EndEdit();

this.tableAdapterManager.UpdateAll(this.DataSet1);

Regards

Chris

6 Replies

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snehal suryavanshi8y ago
Accepted answer
this problem occured because you get null vallue initially for your id

for this your id should be auto incremented
go to identispecification and set isIdentity : true

thank you
Christopher Hankwembo8y ago
That is exactly what I did , I have done the following:

(1) At C# form level, I have not dragged all the primary keys (both parent & child)but only controls which require values
(2) I have also left out the foreign key as well from the dataset

But when saving it still want the primary key in the child table to be updated, that is where the problem is ??????????????????

Regards

Chris
Rafnas T P8y ago
hi,
this all ids are primary keys, so those ids should not null and should not repeate,
you can make all those ids as identity integer or numeric column as I said, then when saving no need to pass this ids,
Christopher Hankwembo8y ago
Again the solution is not sort out the problem

I have another strange problem when trying to save related tables in C# , I keep on receiving an error as below

PersonID is not nullable

Where do I go wrong ???

When I detach the table to remain with a single table everything works okay, I can change data, delete and add new data without problem.

How do I get rid of this not null-able thing, see my two table below, please tell where do I go wrong
Yogesh Ghorpade8y ago
In Table Design Set Staff Id
Rafnas T P8y ago
hi,
this error is due to primary key null, you can not pass null value to primary key value to insert data, for this you can pass staffID value which is not inserted already or
you do not wanted to pass this staffID every time to insert then you can make this staffID as identity column by adding 1 as below

staffID int identity(1,1) primary key

by changing column to identity, no need to pass this column value, when you insert data, this column will insert id increment by 1 automatically