Copy Primary key value into another table as Foreign Key? - foreign-keys

Question

CREATE TRIGGER copy_pk_into_fk_trigger
AFTER insert ON tableA
FOR EACH ROW
BEGIN
insert into tableB (tblA_ID) values (new.tblA_ID);
END$$
i'm using the above trigger to copy the Primary Key value from tableA and inset into the tableB as foreign key. But after that, whenever, i edit the record in tableB using detailsView in ASP.net , the foreign key value goes "NULL". And this cause no more connection b/w parent and child. plz help me.
[tableA having col: tblA_ID, tblA_val and
TableB contains tblB_ID, tblA_ID, tblB_str
etc etc]

Answer 1

I don't think this have something to do with your trigger. As the trigger will only run after an insert has been triggered. Can you show me the query for updating in the detailsView? Are you sure you didn't mentioned the update statement as well?

Answer 2

Here's complete source code of SqlDATASource and DetailsView:
<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:HADIConnectionString %>"
DeleteCommand="DELETE FROM "INDENT_FILE_NO" WHERE "FILE_NO_ID" = :original_FILE_NO_ID AND (("INDENT_ID" = :original_INDENT_ID) OR ("INDENT_ID" IS NULL AND :original_INDENT_ID IS NULL)) AND (("FILE_NO" = :original_FILE_NO) OR ("FILE_NO" IS NULL AND :original_FILE_NO IS NULL)) AND (("FILE_DESCRIPTION" = :original_FILE_DESCRIPTION) OR ("FILE_DESCRIPTION" IS NULL AND :original_FILE_DESCRIPTION IS NULL)) AND (("INDENTER" = :original_INDENTER) OR ("INDENTER" IS NULL AND :original_INDENTER IS NULL))" InsertCommand="INSERT INTO "INDENT_FILE_NO" ("FILE_NO_ID", "INDENT_ID", "FILE_NO", "FILE_DESCRIPTION", "INDENTER") VALUES (:FILE_NO_ID, :INDENT_ID, :FILE_NO, :FILE_DESCRIPTION, :INDENTER)" OldValuesParameterFormatString="original_{0}" ProviderName="<%$ ConnectionStrings:HADIConnectionString.ProviderName %>"
SelectCommand="SELECT * FROM "INDENT_FILE_NO" WHERE ("INDENT_ID" = :INDENT_ID)"
UpdateCommand="UPDATE "INDENT_FILE_NO" SET "INDENT_ID" = :INDENT_ID, "FILE_NO" = :FILE_NO, "FILE_DESCRIPTION" = :FILE_DESCRIPTION, "INDENTER" = :INDENTER WHERE "FILE_NO_ID" = :original_FILE_NO_ID AND (("INDENT_ID" = :original_INDENT_ID) OR ("INDENT_ID" IS NULL AND :original_INDENT_ID IS NULL)) AND (("FILE_NO" = :original_FILE_NO) OR ("FILE_NO" IS NULL AND :original_FILE_NO IS NULL)) AND (("FILE_DESCRIPTION" = :original_FILE_DESCRIPTION) OR ("FILE_DESCRIPTION" IS NULL AND :original_FILE_DESCRIPTION IS NULL)) AND (("INDENTER" = :original_INDENTER) OR ("INDENTER" IS NULL AND :original_INDENTER IS NULL))" ConflictDetection="CompareAllValues">
<UpdateParameters>
<asp:Parameter Name="INDENT_ID" Type="Decimal" />
<asp:Parameter Name="FILE_NO" Type="String" />
<asp:Parameter Name="FILE_DESCRIPTION" Type="String" />
<asp:Parameter Name="INDENTER" Type="String" />
<asp:Parameter Name="original_FILE_NO_ID" Type="Decimal" />
<asp:Parameter Name="original_INDENT_ID" Type="Decimal" />
<asp:Parameter Name="original_FILE_NO" Type="String" />
<asp:Parameter Name="original_FILE_DESCRIPTION" Type="String" />
<asp:Parameter Name="original_INDENTER" Type="String" />
</UpdateParameters>
Details View :
<asp:DetailsView ID="DetailsView2" runat="server" AutoGenerateRows="False" DataKeyNames="FILE_NO_ID" DataSourceID="SqlDataSource2" Height="50px" Width="287px" >
<Fields>
<asp:BoundField DataField="FILE_NO_ID" HeaderText="FILE_NO_ID" ReadOnly="True" SortExpression="FILE_NO_ID" Visible="False" />
<asp:BoundField DataField="INDENT_ID" HeaderText="INDENT_ID" SortExpression="INDENT_ID" Visible="False" />
<asp:BoundField DataField="FILE_NO" HeaderText="FILE_NO" SortExpression="FILE_NO" />
<asp:BoundField DataField="FILE_DESCRIPTION" HeaderText="FILE_DESCRIPTION" SortExpression="FILE_DESCRIPTION" />
<asp:BoundField DataField="INDENTER" HeaderText="INDENTER" SortExpression="INDENTER" />
<asp:CommandField ShowEditButton="True" ButtonType="Button" />
</Fields>
</asp:DetailsView>
But now, when i press the edit button and edit the fields and then update them, the data of that fields remains same. Means no action takes.