我的 ComboBox
控件显示 publishername 和 authorlastname 并存储 publisherid 和 authorid。
当我运行我的代码时,它会显示 publishername 和 authorlastname 以及 publisherid 和 ValueMember
em>authorid 然而,当插入查询运行时,它会尝试插入单词 _publisherid_
和 _authorid_
。
组合框代码:
Private Sub addbook_Load(sender As Object, e As EventArgs) Handles MyBase.Load
mysqlconn = New MySqlConnection
mysqlconn.ConnectionString = "server=localhost;userid=root;database=librarydatabase;Convert Zero Datetime=True"
Dim table As New DataTable
Dim da As New MySqlDataAdapter("select * from publishertable", mysqlconn)
da.Fill(table)
ComboBox1.DataSource = New BindingSource(table, Nothing)
ComboBox1.DisplayMember = "publishername"
ComboBox1.ValueMember = "PublisherId"
Dim pa As New MySqlDataAdapter("select * from authortable", mysqlconn)
pa.Fill(table)
ComboBox2.DataSource = New BindingSource(table, Nothing)
ComboBox2.DisplayMember = "authorlastname"
ComboBox2.ValueMember = "authorid"
End Sub
插入代码:
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button1.Click
conn = New MySqlConnection
conn.ConnectionString =
"server=localhost;userid=root;database=librarydatabase"
Dim reader As MySqlDataReader
Try
conn.Open()
query = "SET foreign_key_checks = 0;insert into booktable(ISBNno,bookname,dateofpublication,genre,duodecimal,copies,copiesinstock,authorid,publisherid) Values('" & ISBNno.Text & "','" & Title.Text & "','" & dateofpublication.Text & "','" & genre.Text & "','" & duodecimal.Text & "','" & copies.Text & "','" & copies.Text & "','" & ComboBox2.ValueMember & "', '" & ComboBox1.ValueMember & "');SET foreign_key_checks = 1"
command = New MySqlCommand(query, conn)
reader = command.ExecuteReader
MessageBox.Show(query)
conn.Close()
Catch ex As MySqlException
MessageBox.Show(ex.Message)
Finally
conn.Dispose()
End Try
End Sub
最佳答案
您应该使用 SelectedValue 而不是 ValueMember
query = "SET foreign_key_checks = 0;insert into booktable(ISBNno,bookname,dateofpublication,genre,duodecimal,copies,copiesinstock,authorid,publisherid) Values('" & ISBNno.Text & "','" & Title.Text & "','" & dateofpublication.Text & "','" & genre.Text & "','" & duodecimal.Text & "','" & copies.Text & "','" & copies.Text & "','" & ComboBox2.ValueMember & "', '" & ComboBox1.ValueMember & "');SET foreign_key_checks = 1"
应该是
query = "SET foreign_key_checks = 0;insert into booktable(ISBNno,bookname,dateofpublication,genre,duodecimal,copies,copiesinstock,authorid,publisherid) Values('" & ISBNno.Text & "','" & Title.Text & "','" & dateofpublication.Text & "','" & genre.Text & "','" & duodecimal.Text & "','" & copies.Text & "','" & copies.Text & "','" & ComboBox2.SelectedValue & "', '" & ComboBox1.SelectedValue & "');SET foreign_key_checks = 1"
关于mysql - Combobox ValueMember 不适用于 MySQL,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40785159/