Question

上下文：Web应用程序（asp.net）使用FormView编辑并将pupil数据插入SQL Server数据库。错误：

System.Data.SqlClient.SqlException：无法将值NULL插入列'txtSchoolID'，表'iSAMS.dbo.TblPupilManagementPupils';列不允许空值。 INSERT失败。

我有一个包含FormView控件的aspx页面，该控件包含（编辑，插入和读取）模板和按钮（用于更新和插入数据）。该插件使用onclick事件处理程序在TblPupilManagementPupils表中插入新行。

此表包含（在其他列中）具有以下属性的主键：

Identity: True
Identity seed: 1
Identity Increment: 1
Data type: int
Primary key: true
Allow nulls: false

在codebehond文件中，我使用objectcontext来注册实体集合并提交新对象。见下文：

protected void btnInsertCandidate_onClick(object sender, EventArgs e)
{
            //string SchoolCode = ((Label)selectedCandidateFormView.FindControl("lblCandidateKey")).Text;
            string FirstName = ((TextBox)selectedCandidateFormView.FindControl("txbFirstName")).Text;
            string LastName = ((TextBox)selectedCandidateFormView.FindControl("txbLastName")).Text;
            string PreName = ((TextBox)selectedCandidateFormView.FindControl("txbPreName")).Text;
            string Gender = ((TextBox)selectedCandidateFormView.FindControl("txbGender")).Text;
            string DOB = ((TextBox)selectedCandidateFormView.FindControl("txbCandidateDOB")).Text;
            string YoE = ((TextBox)selectedCandidateFormView.FindControl("txbCandidateYearOfEntry")).Text;
            string NCEY = ((DropDownList)selectedCandidateFormView.FindControl("ddlCandidateNCEntryYear")).SelectedValue.ToString();
            string BoardingType = ((DropDownList)selectedCandidateFormView.FindControl("ddlCandidateBoardingType")).SelectedValue.ToString();
            string Languages = ((TextBox)selectedCandidateFormView.FindControl("txbCandidateLanguage")).Text;
            string Nationalities = ((TextBox)selectedCandidateFormView.FindControl("txbCandidateNationality")).Text;

            // insert a new candidate into iSAMS (pupil record) via LINQ. Effectively copying a candidate from Admissions into a new pupil row in iSAMS.
            using (AdmissionsVerificationApplication.iSAMSEntities iSAMSContext = new AdmissionsVerificationApplication.iSAMSEntities())
            {
                TblPupilManagementPupil pupil = new TblPupilManagementPupil()
                {
                    txtForename = FirstName,
                    txtSurname = LastName,
                    txtPreName = PreName,
                    txtGender = Gender,
                    txtDOB = Convert.ToDateTime(DOB),
                    intEnrolmentSchoolYear = Convert.ToInt32(YoE),
                    intEnrolmentNCYear = Convert.ToInt32(NCEY),
                    txtType = BoardingType,
                    txtLanguage = Languages,
                    txtNationality = Nationalities
                };       

                iSAMSContext.TblPupilManagementPupils.AddObject(pupil);
                iSAMSContext.SaveChanges();
        }
}

我还检查了.edmx文件，以确保ID列具有正确的属性 edmx：StorageModels标记：

    <EntityType Name="TblPupilManagementPupils">
      <Key>
        <PropertyRef Name="TblPupilManagementPupilsID" />
      </Key>
      <Property Name="TblPupilManagementPupilsID" Type="int" Nullable="false" StoreGeneratedPattern="Identity" />

...

为了完整性（我认为！），这是生成的edmx设计器文件中的相关部分：

public partial class TblPupilManagementPupil : EntityObject
{
    #region Factory Method

    /// <summary>
    /// Create a new TblPupilManagementPupil object.
    /// </summary>
    /// <param name="tblPupilManagementPupilsID">Initial value of the TblPupilManagementPupilsID property.</param>
    /// <param name="txtSchoolID">Initial value of the txtSchoolID property.</param>
    public static TblPupilManagementPupil CreateTblPupilManagementPupil(global::System.Int32 tblPupilManagementPupilsID, global::System.String txtSchoolID)
    {
        TblPupilManagementPupil tblPupilManagementPupil = new TblPupilManagementPupil();
        tblPupilManagementPupil.TblPupilManagementPupilsID = tblPupilManagementPupilsID;
        tblPupilManagementPupil.txtSchoolID = txtSchoolID;
        return tblPupilManagementPupil;
    }

    #endregion
    #region Primitive Properties

    /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)]
    [DataMemberAttribute()]
    public global::System.Int32 TblPupilManagementPupilsID
    {
        get
        {
            return _TblPupilManagementPupilsID;
        }
        set
        {
            if (_TblPupilManagementPupilsID != value)
            {
                OnTblPupilManagementPupilsIDChanging(value);
                ReportPropertyChanging("TblPupilManagementPupilsID");
                _TblPupilManagementPupilsID = StructuralObject.SetValidValue(value);
                ReportPropertyChanged("TblPupilManagementPupilsID");
                OnTblPupilManagementPupilsIDChanged();
            }
        }
    }
    private global::System.Int32 _TblPupilManagementPupilsID;
    partial void OnTblPupilManagementPupilsIDChanging(global::System.Int32 value);
    partial void OnTblPupilManagementPupilsIDChanged();

.....

我在某处读到可能需要设置属性IsDBGenerated以指示映射使用DB进行ID生成....但由于这是生成的文件，我不知道如何添加属性。如果确实是这个问题。

任何帮助都会得到很好的接受。

此致

百里

Answer 1

原因是因为未设置iSAMS.dbo.TblPupilManagementPupils表的txtSchoolID属性。您需要设置学校ID或将列设置为允许NULL。

Web应用程序抛出'无法INSERT null ....列不允许NULLS

1 个答案: