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上下文：Web 应用程序 (asp.net) 使用 FormView 编辑学生数据并将其插入 SQL Server DB。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。插入失败。

我有一个包含FormView控件的 aspx 页面，该控件包含（编辑、插入和只读）模板和按钮（用于更新和插入数据）。插入使用 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：

身份：真
身份种子：1
身份增量：1
数据类型：int
主键：真
允许空值：false

在代码隐藏文件中，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 列在 edmx:StorageModels 标记下具有正确的属性：

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

……

为了完整起见（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 生成 ID .... 但由于这是一个生成的文件，我不确定如何添加该属性。如果确实是这个问题。

任何帮助都将受到极大的欢迎。

问候

巴里

4

1 回答 1

0

原因是没有设置iSAMS.dbo.TblPupilManagementPupils表的属性。txtSchoolID您需要设置学校 ID 或将列设置为允许NULL。

于 2013-03-15T11:23:26.263 回答