ADO.NET SAVE FUNCTION ERROR

Question

Sir I am getting a message while saving a form in ADO.NET I think it is the conflict between foreign key constraint. This is the error . could you explain me why i getting this error?

Sandeep Singh Shekhawat · Answer

Hi Bineesh Here tbl_Division is referenced table where row would be insert first and tbl_Student is child table where row would be insert after. Allow null means it can have null values its not matter when it is not used as reference filed for foreign key. But it is using as reference field b/w these two table and DivisionId is primary key in table tbl_Division so it can't not be null in table tbl_Division so it also can't be null in tbl_Student also because it is foreign key in table tbl_Student.We know that DesisionId will not be null in tbl_Division so its child table tbl_Student DivisionId field can't be null. Suppose we insert a null value in child table tbl_Student DivisionId field that how can we map this value in refernced table tbl_Division?

Bineesh VP · Answer

Ya you are in right path as I expected. I have a table named tbl_Division and tbl_Student. here the table where divisionId is PK; I write code in the btnSave Click event in frmStudent is; infostudent.divisionId=decimal.parse(cmbdivision.selectedindex.Tostring()); I checked in its Allow Null column in tbl_Student. here is the tbl_Student. you can see the allow nulls column of divisionId is checked. Is this the problem? which is referenced table and child table? please explain

Kunal Vaishya · Answer

Hi  I think you are passing 0(zero) or blank (null) foreign key check value which you have pass.

Sandeep Singh Shekhawat · Answer

You are getting error by a value which is inserting in division field. You have two table that has foreign key relation on divisionId field. You should first insert value in your referenced table afterthat value will be insert in child table. So first execute insert statement for referenced table thereafter you execute your insert query. Thanks