MSSQL+winforms

  • Thread starter Thread starter Balint Toth
  • Start date Start date
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Balint Toth

Hi all,

I am very new to database. I created two tables, and I have two user
controls on my winforms application. In the first usercontrol I use the
first table, in the secund, the secund one.

In the MainForm I have to make some processing with them, I make some
queries with the JOIN of the two tables. But unfortunately it doesn't works,
it sais:

"Additional information: Failed to enable constraints. One or more rows
contain values violating non-null, unique, or foreign-key constraints."

I think the problem is, that the MainForm opens the connection and the
tables, and when the user control tries to open the table, it causes
violation, but I am not sure.

What can be the problem? How can I solve it?

Thanks in advance!

Best regards,
Bálint Tóth
 
Hi Balint:
Balint Toth said:
Hi all,

I am very new to database. I created two tables, and I have two user
controls on my winforms application. In the first usercontrol I use the
first table, in the secund, the secund one.

In the MainForm I have to make some processing with them, I make some
queries with the JOIN of the two tables. But unfortunately it doesn't works,
it sais:
Click to expand...

You should probably opt away from the join and do two fills and connect the
tables with a datarelation.
"Additional information: Failed to enable constraints. One or more rows
contain values violating non-null, unique, or foreign-key constraints."

I think the problem is, that the MainForm opens the connection and the
tables, and when the user control tries to open the table, it causes
violation, but I am not sure.
Click to expand...
Something is violating the schema of your table, and depending on the way
its set up and the respective schema, you are violating one of your own
rules.

I don't think opening the tables has anything to do with it. When are you
getting the exception too? On dataAdapter.Fill?
What can be the problem? How can I solve it?

Thanks in advance!

Best regards,
Bálint Tóth
Click to expand...

Let me know and we'll get you through it.

HTH,

Bill

www.devbuzz.com
www.knowdotnet.com
 
Hi,

yes, I get the exception on dataAdapter.Fill.
I tried the DataRelation, but I got the following exception:
Additional information: This constraint cannot be enabled as not all values
have corresponding parent values.
My source code (I got a table containing url addresses, and emails, with a
url_id field, what tells which email address belongs to which url - more
emails can belong to one url, but not vica versa):

DataColumn parentCol;

DataColumn childCol;

parentCol = dsEmails.Tables["urls"].Columns["id"];

childCol = dsEmails.Tables["emails"].Columns["url_id"];

DataRelation relUrlEmail;

relUrlEmail = new DataRelation("EmailUrl", parentCol, childCol, true);

dsEmails.Relations.Add(relUrlEmail);

Thanks for your help in advance!

Best regards,
Balint Toth
 
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