Database 更新数据库时出现问题

我附上代码以供参考。我正在尝试为我的项目详细信息创建数据库。我目前有两份表格：

主要形式

项目详情表

用于切换各种窗体的主窗体

项目详细信息表单用于添加/编辑/加载项目详细信息

我在VisualBasic中的主要表单如下所示

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    End Sub

    Private Sub Bt_Project_Details_Click(sender As Object, e As EventArgs) Handles Bt_Project_Details.Click
        Me.Hide()
        Project_Details_Form.Show()
    End Sub
End Class

Public Class Project_Details_Form

    Private Sub Project_Details_Form_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'Project_Data_Set.Project_Data_Table' table. You can move, or remove it, as needed.
        Me.Project_Data_TableTableAdapter.Fill(Me.Project_Data_Set.Project_Data_Table)
    End Sub

    Private Sub Bt_Load_Project_Click(sender As Object, e As EventArgs) Handles Bt_Load_Project.Click
    End Sub

    Private Sub Bt_Cancel_Click(sender As Object, e As EventArgs) Handles Bt_Cancel.Click
        Me.Hide()
        Form1.Show()
    End Sub

    Private Sub BindingNavigatorAddNewItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorAddNewItem.Click
        Project_Data_TableBindingSource.AddNew()
    End Sub

    Private Sub Project_Data_TableBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles Project_Data_TableBindingNavigatorSaveItem.Click
        Me.Validate()
        Me.Project_Data_TableBindingSource.EndEdit()
        Me.TableAdapterManager.UpdateAll(Me.Project_Data_Set)
    End Sub

    Private Sub BindingNavigatorDeleteItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorDeleteItem.Click
        Project_Data_TableBindingSource.RemoveCurrent()
    End Sub

    Private Sub FillByToolStripButton_Click(sender As Object, e As EventArgs)
        Try
            Me.Project_Data_TableTableAdapter.FillBy(Me.Project_Data_Set.Project_Data_Table)
        Catch ex As System.Exception
            System.Windows.Forms.MessageBox.Show(ex.Message)
        End Try

    End Sub
End Class

我的项目详细信息表单如下所示

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    End Sub

    Private Sub Bt_Project_Details_Click(sender As Object, e As EventArgs) Handles Bt_Project_Details.Click
        Me.Hide()
        Project_Details_Form.Show()
    End Sub
End Class

Public Class Project_Details_Form

    Private Sub Project_Details_Form_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'Project_Data_Set.Project_Data_Table' table. You can move, or remove it, as needed.
        Me.Project_Data_TableTableAdapter.Fill(Me.Project_Data_Set.Project_Data_Table)
    End Sub

    Private Sub Bt_Load_Project_Click(sender As Object, e As EventArgs) Handles Bt_Load_Project.Click
    End Sub

    Private Sub Bt_Cancel_Click(sender As Object, e As EventArgs) Handles Bt_Cancel.Click
        Me.Hide()
        Form1.Show()
    End Sub

    Private Sub BindingNavigatorAddNewItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorAddNewItem.Click
        Project_Data_TableBindingSource.AddNew()
    End Sub

    Private Sub Project_Data_TableBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles Project_Data_TableBindingNavigatorSaveItem.Click
        Me.Validate()
        Me.Project_Data_TableBindingSource.EndEdit()
        Me.TableAdapterManager.UpdateAll(Me.Project_Data_Set)
    End Sub

    Private Sub BindingNavigatorDeleteItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorDeleteItem.Click
        Project_Data_TableBindingSource.RemoveCurrent()
    End Sub

    Private Sub FillByToolStripButton_Click(sender As Object, e As EventArgs)
        Try
            Me.Project_Data_TableTableAdapter.FillBy(Me.Project_Data_Set.Project_Data_Table)
        Catch ex As System.Exception
            System.Windows.Forms.MessageBox.Show(ex.Message)
        End Try

    End Sub
End Class

现在我面临几个问题：

每当我运行程序时，尝试输入保存的第一个条目数据，但值为空。数据将在下次正确存储时输入。如何使我的第一个条目可见

在以下代码中：

Private Sub BindingNavigatorAddNewItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorAddNewItem.Click
    Project_Data_TableBindingSource.AddNew()

End Sub

我正在使用

AddNew（）

。这工作正常，但问题是，即使我不输入数据，如日期，名称保持为空，数据记录在他们的立场是存储空只。我想说，如果任何项目数据集是空的，请给出错误消息（因为用户必须输入这些数据）

---

是否有其他方法可以单独赋值。 像我的项目数据库包含项目名称，客户名称等，如果我说新按钮按下清除所有字段。一旦表单填写完毕，按下保存按钮，记录单个值

Private Sub BindingNavigatorAddNewItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorAddNewItem.Click
        Project_Data_TableBindingSource.AddNew()
    End Sub

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如果您想了解VB（实际上是VB.NET；只是假定Visual Basic是旧的VB6，在.NET之前），为什么要添加VBA标记（一种完全不同的语言）？正确标记你的问题，最好不要在标题中添加（不准确的）编程语言引用。我是初学者。我正在用visual basic编写代码。@varocarbas是什么让你认为我在这里行为不端。我已经发布了我的代码。我希望它确实满足您在

项目中询问的问题要求\u数据\u表格绑定导航器保存项目\u单击
子项您需要在保存之前检查是否添加了任何数据。