Question

我正在VB.Net和SQL Server中创建LMS。书中添加表单包含文本框组合框和图片框。当我单击“保存”按钮时，它会显示以下错误消息

Conversion failed when converting the varchar value 'Saman' to data type int.

在表单加载上，组合框填充整个表中的数据。

表和关系

要插入的数据

数据类型为

的表格

保存时出现错误信息

我尝试了以下编码

表单加载编码

Private Sub frmAddBook_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    'To load Author details
    Using com As New SqlCommand("SELECT * FROM tblBookAuthor", con)

        Dim dt As New DataTable()
        dt.Load(com.ExecuteReader)
        cmbAuthor.DataSource = dt
        cmbAuthor.DisplayMember = "authorFirstName"
        cmbAuthor.ValueMember = "authorFirstName"
        ' con.Close()
    End Using

    'To load Publisher details
    Using com2 As New SqlCommand("SELECT * FROM tblPublisher", con)

        Dim dt As New DataTable()
        dt.Load(com2.ExecuteReader)
        cmbPub.DataSource = dt
        cmbPub.DisplayMember = "publisherName"
        cmbPub.ValueMember = "publisherName"

        ' con.Close()
    End Using

    'To load Class details
    Using com3 As New SqlCommand("SELECT * FROM tblBookClass", con)

        Dim dt As New DataTable()
        dt.Load(com3.ExecuteReader)
        cmbClass.DataSource = dt
        cmbClass.DisplayMember = "classDetail"
        cmbClass.ValueMember = "classDetail"
        ' con.Close()
    End Using

    'To load bookshelf details
    Using com4 As New SqlCommand("SELECT * FROM tblBookShelfDetail", con)

        Dim dt As New DataTable()
        dt.Load(com4.ExecuteReader)
        cmbBookShelf.DataSource = dt
        cmbBookShelf.DisplayMember = "shelfDetail"
        cmbBookShelf.ValueMember = "shelfDetail"
        con.Close()
    End Using

End Sub

保存按钮编码

Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click

    sql = "INSERT INTO tblBookDetail (accessionNo, authorId, title, pages, price, ISBN, noOfCopies, pubId, classId, source, bookShelfNo,bookEdition, bookCoverImg) VALUES (@accNo, @auID, @title, @pages, @price, @ISBN, @noOfCopies, @pubID, @classID, @src, @shlfNo, @edition, @img)"

    Dim ms As New MemoryStream()
    picPhoto.Image.Save(ms, picPhoto.Image.RawFormat)

    con.Open()
    cmd = New SqlCommand(sql, con)

    cmd.Parameters.Add("@accNo", SqlDbType.Int).Value = txtBookID.Text
    cmd.Parameters.Add("@auID", SqlDbType.VarChar).Value = cmbAuthor.Text
    cmd.Parameters.Add("@title", SqlDbType.VarChar).Value = txtEdition.Text
    cmd.Parameters.Add("@pages", SqlDbType.Int).Value = txtPageNo.Text
    cmd.Parameters.Add("@price", SqlDbType.Decimal).Value = txtPrice.Text
    cmd.Parameters.Add("@ISBN", SqlDbType.Int).Value = txtISBN.Text
    cmd.Parameters.Add("@noOfCopies", SqlDbType.Int).Value = txtNoOfCopies.Text
    cmd.Parameters.Add("@pubID", SqlDbType.VarChar).Value = cmbPub.Text
    cmd.Parameters.Add("@classID", SqlDbType.VarChar).Value = cmbClass.Text
    cmd.Parameters.Add("@src", SqlDbType.VarChar).Value = cmbSrc.Text
    cmd.Parameters.Add("@shlfNo", SqlDbType.VarChar).Value = cmbBookShelf.Text
    cmd.Parameters.Add("@edition", SqlDbType.Int).Value = txtEdition.Text

    cmd.Parameters.Add("@img", SqlDbType.Image).Value = ms.ToArray

    cmd.ExecuteNonQuery()

    MsgBox("SUCCESS")
    con.Close()

End Sub

Answer 1

程序错误：

将varchar值'Saman'转换为数据时转换失败输入int。

在这里，你将列authorID作为数据类型整数，那你怎么能插入varchar，即将'Saman'命名为它！

触发此错误的代码行：

cmd.Parameters.Add("@auID", SqlDbType.VarChar).Value = cmbAuthor.Text

确保表格列不是整数或相应更改。

修改：

如果要插入id，则：

用组合框中的SelectedValue替换文本

希望你明白这一点。感谢

VB.Net在将数据保存到SQL Server时触发错误

1 个答案: