VB连接数据库失败的解决方法
用VB做了一个管理系统,用到数据库查询,由于系统在局域网内使用的,所以有时候会碰到路由器断电或者网线掉线等情况发生,这是VB数据库查询错误,强制退出系统,有没有什么方法解决一下,可以在数据库连接不上时提示操作用户检查出现的问题,但是不要退出管理系统。下面是我用的连接数据库的代码:
Public Function ConnectString() _
As String
ConnectString = "Provider=SQLOLEDB.1;User ID=sa;password=12345633;Initial Catalog=carddatabase;Data Source=" & IPstr
End Function
Public Function ExecuteSQL(ByVal SQL _
As String, MsgString As String) _
As ADODB.Recordset
'executes SQL and returns Recordset
Dim cnn As ADODB.Connection
Dim rst As ADODB.Recordset
Dim sTokens() As String
On Error GoTo ExecuteSQL_Error
sTokens = Split(SQL)
Set cnn = New ADODB.Connection
cnn.Open ConnectString
If InStr("INSERT,DELETE,UPDATE", _
UCase$(sTokens(0))) Then
cnn.Execute SQL
MsgString = sTokens(0) & _
" query successful"
Else
Set rst = New ADODB.Recordset
rst.CursorLocation = 3
rst.Open Trim$(SQL), cnn, _
adOpenKeyset, _
adLockOptimistic
'rst.MoveLast 'get RecordCount
Set ExecuteSQL = rst
MsgString = "查询到" & rst.RecordCount & _
" 条记录 "
End If
ExecuteSQL_Exit:
Set rst = Nothing
Set cnn = Nothing
Exit Function
ExecuteSQL_Error:
MsgString = "查询错误: " & _
Err.Description
Resume ExecuteSQL_Exit
End Function