从bll到mysql的ASP.NET插入

Question

I am trying to make an insert to an MySql database using a three layer solution (or what it might be called).

I have done this may times with an MS-sql database and it has worked very well.

But now when I am trying to make an insert I get the the ID can't be null. I thought the database took care of that. If I write an insert directly in the code and use the MySqlCommand and executeNonQuery it works great.

Is it not possible to use BLL and DAL with MySql?

Error message:

System.Data.NoNullAllowedException: Column 'GiftID' does not allow nulls. at System.Data.DataColumn.CheckNullable(DataRow row) at System.Data.DataColumn.CheckColumnConstraint(DataRow row, DataRowAction action) at System.Data.DataTable.RaiseRowChanging(DataRowChangeEventArgs args, DataRow eRow, DataRowAction eAction, Boolean fireEvent) at System.Data.DataTable.SetNewRecordWorker(DataRow row, Int32 proposedRecord, DataRowAction action, Boolean isInMerge, Int32 position, Boolean fireEvent, Exception& deferredException) at System.Data.DataTable.InsertRow(DataRow row, Int32 proposedID, Int32 pos, Boolean fireEvent) at System.Data.DataRowCollection.Add(DataRow row) at PayEx.payexusersDataTable.AddpayexusersRow(payexusersRow row) in c:\\Users\\IT\\AppData\\Local\\Temp\\Temporary ASP.NET Files\\payex\\45bd406a\\10c84208\\App_Code.cyqhjqo7.1.cs:line 444 at PayExBLL.AddPayExUser(String Firstname, String Lastname, String Company, String Address, String Zip, String City, String Phone, String Email, Byte ContactMe, UInt32 Amount, UInt32 TransactionNumber, Byte Anonymous, String Cu rrency) in c:\\Users\\IT\\Documents\\Visual Studio 2008\\WebSites\\payex\\App_Code\\BLL\\PayExBLL.cs:line 66 at _Default.btn_next3_Click(Object sender, EventArgs e) in c:\\Users\\IT\\Documents\\Visual Studio 2008\\WebSites\\payex\\Default.aspx.cs:line 191

My code:

[System.ComponentModel.DataObjectMethodAttribute(System.ComponentModel.DataObjectMethodType.Insert, true)]
public bool AddPayExUser(string Firstname, string Lastname, string Company, string Address, string Zip, string City, string Phone, string Email, byte ContactMe, uint Amount, uint TransactionNumber, byte Anonymous, string Currency)
{
    PayEx.payexusersDataTable puTable = new PayEx.payexusersDataTable();
    PayEx.payexusersRow puRow = puTable.NewpayexusersRow();

    puRow.Firstname = Firstname;
    puRow.Lastname  = Lastname;
    puRow.Company = Company;
    puRow.Address = Address;
    puRow.Zip = Zip;
    puRow.City = City;
    puRow.Phone = Phone;
    puRow.Email = Email;
    puRow.ContactMe = ContactMe;
    puRow.Amount = Amount;
    puRow.TransactionNumber = TransactionNumber;
    puRow.Anonymous = Anonymous;
    puRow.Currency = Currency;


    puTable.AddpayexusersRow(puRow);
    int rowsAffected = Adapter.Update(puTable);

    return rowsAffected == 1;
}

Answer 1

System.Data.NoNullAllowedException: Column 'GiftID' does not allow nulls. at 

From the looks of your code, you're forgetting to pass in a GiftID parameter to your function but it's expected (and can't be null) in your table row.

Hence the exception. Either set it in your code above, or define a default value on it in your MySQL database.

Answer 2

EDIT: This comment assumes you're inserting into a table for which GiftId is the primary key, which seems unlikely. If so, Eoin Campbell's answer makes more sense!

Check if GiftId is an AUTO_INCREMENT column; that's MySQL's equivalent of identity.

You can recreate the column as identity like:

ALTER TABLE Gifts
         DROP COLUMN GiftId;

ALTER TABLE items
         ADD COLUMN GiftId INT NOT NULL AUTO_INCREMENT FIRST;