UC知道vb中简单问题
来源：百度知道 编辑：UC知道 时间：2024/06/05 13:33:45
写了一个简单的管理系统，请问如何屏蔽combo2里的重复项，然后要access表里的数据按学号字段排列？
Private Sub Combo1_Click()
Combo2.Clear
Dim SQL As String
Dim rs As New ADODB.Recordset
Dim connectionstring As String
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb;"
conn.Open connectionstring
SQL = "select * from students where 班级 =" & Combo1.Text & ""
Set rs = conn.Execute(SQL)
While rs.EOF = False
Combo2.AddItem rs.Fields(2)
rs.MoveNext
Wend
End Sub
Private Sub Combo2_click()
Dim SQL As String
Dim rs As New ADODB.Recordset
Dim connectionstring As String
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb;"
conn.Open
Private Sub Combo1_Click()
Combo2.Clear
Dim SQL As String
Dim rs As New ADODB.Recordset
Dim connectionstring As String
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb;"
conn.Open connectionstring
SQL = "select * from students where 班级 =" & Combo1.Text & ""
Set rs = conn.Execute(SQL)
While rs.EOF = False
Combo2.AddItem rs.Fields(2)
rs.MoveNext
Wend
End Sub
Private Sub Combo2_click()
Dim SQL As String
Dim rs As New ADODB.Recordset
Dim connectionstring As String
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb;"
conn.Open
SQL = "select * from students where 班级 =" & Combo1.Text & "'order by 学号 desc"
Set rs = conn.Execute(SQL)
While rs.EOF = False
i=0
for 0 to Combo2.ListCount - 1
If Combo2.List(i) = rs.Fields(2) Then i = i + 1
next
if i=0 then
Combo2.AddItem rs.Fields(2)
end if
rs.MoveNext
Wend
End Sub
看得头疼啊~~~~
建议关于数据库的操作都写成函数放到模块里，程序中只用改sql语句就行了，那么长一串代码，看得好烦
1.请问如何屏蔽combo2里的重复项
在sql中用distinct 唯一化该字段
比如你加到combo中的字段名为姓名
SQL = "select distinct 姓名 from students where 班级 =" & Combo1.Text & ""
2.然后要access表里的数据按学号字段排列？
sql中用order by 学号
SQL = "select * from students where 姓名='" & Combo2.Text & "' and 课程 ='" & Combo3.Text & "' and 班级 =" & Combo1.Text & " order by 学号 "
下面是一个完整版本的。。。
Private Sub Combo1_Click()
Combo2.Clear
Dim SQL