Private Sub Form10_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim myconn As New SqlConnection("database = maths;data source =DESKTOP-SDCVCMC\SQLEXPRESS;integrated security = true;")
Dim mysql As String = "select distinct 教材编号 from 教材"
Dim myadapter As New SqlDataAdapter(mysql, myconn)
Dim mydataset As New DataSet
myadapter.Fill(mydataset, "教材编号__")
Me.ComboBox2.DataSource = mydataset.Tables("教材编号__")
Me.ComboBox2.DisplayMember = "教材编号"
End Sub
/////////////////////////////////////////////////
Private Sub ComboBox2_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox2.SelectedIndexChanged
Dim myconn As New SqlConnection("database = maths;data source =DESKTOP-SDCVCMC\SQLEXPRESS;integrated security = true;")
Dim mysql As String = "select distinct 教材名称 from 教材 where 教材编号 = ' " & Me.ComboBox2.Text.Trim & " ' "
Dim myadapter As New SqlDataAdapter(mysql, myconn)
Dim mydataset As New DataSet
myadapter.Fill(mydataset, "教材-")
If (mydataset.Tables("教材-").Rows.Count > 0) Then
Me.TextBox4.Text = mydataset.Tables("教材-").Rows(0).Item(0)
Else
Me.TextBox4.Text = " "
End If
//////////////////////////////////////
Dim mysql As String = "select distinct 教材名称 from 教材 where 教材编号 = ' " & Me.ComboBox2.Text.Trim & " ' "这一句话sql里可以查出来啊？