小弟最近在做sql server数据库课程设计。想问下怎么样才能连接上sql server，如何写代码进行输入，更新，删除等数据库操作。谢谢了！

失误了，我用的是VB，忘写了。不好意思！

Option Explicit

Public Const Conn As String = "Provider=SQLOLEDB.1;Persist Security Info=False;" & _
"User ID=sa;PWD=sa;Initial Catalog=hr;Data Source=127.0.0.1"
'hr是数据库名称  Catalong=数据库名称

Private IsConnect As Boolean
Private cnn As ADODB.Connection
Private rs As ADODB.Recordset


Public Sub Db_Connect()

If IsConnect = True Then
  Exit Sub
End If
Set cnn = New ADODB.Connection

cnn.ConnectionString = Conn
cnn.Open
If cnn.State <> adStateOpen Then
   MsgBox "链接数据库失败"
 End
End If

IsConnect = True


End Sub

Public Sub Db_Disconnect()
  If IsConnect = False Then
   Exit Sub
  End If
  cnn.Close
  IsConnect = False
  

End Sub

'只用来执行Insert，update，delete语句
Public Sub sqlExt(tmpSql As String)
Dim cmd As New
 DbConnect
 Set cmd.ActiveConnection = cnn
  = tmpSql
 cmd.Execute
 Set cmd = noting
 Db_Disconnect
 
End Sub

查询的 程序
Public Function QueryExt(tmpSql As String) As ADODB.Recordset
Dim rst As New ADODB.Recordset
Db_Connect
Set rst.ActiveConnection = cnn
rst.CursorType = adOpenDynamic
rst.LockType = adLockOptimistic
rst.Open tmpSql
Set QueryExt = rst

End Function

Option Explicit

链接数据库的字符串
Public Const Conn As String = "Provider=SQLOLEDB.1;Persist Security Info=False;" & _
"User ID=sa;PWD=sa;Initial Catalog=hr;Data Source=127.0.0.1"
'hr是数据库名称  Catalong=数据库名称

Private IsConnect As Boolean             判读数据库是否链接
Private cnn As ADODB.Connection        链接数据库的connection对象
Private rs As ADODB.Recordset           保存结果集的recordset对象

数据库链接程序
Public Sub Db_Connect()

如果链接标记为真 返回
If IsConnect = True Then
  Exit Sub
End If

关键字New用来创建新对象cnn
Set cnn = New ADODB.Connection
设置cnn的链接字符串的connectstring属性
cnn.ConnectionString = Conn
打开数据库
cnn.Open
判断链接状态
If cnn.State <> adStateOpen Then
如果不成功  显示提示 退出程序
   MsgBox "链接数据库失败"
 End
End If
设置链接标记  表示已经链接到数据库
IsConnect = True
End Sub

断开数据库的链接程序
Public Sub Db_Disconnect()
如果链接标记为假，表明已经断开 直接返回
  If IsConnect = False Then
   Exit Sub
  End If
关闭链接
  cnn.Close
设置链接标记，表明已经断开链接
  IsConnect = False
  
End Sub


'只用来执行Insert，update，delete语句
Public Sub sqlExt(tmpSql As String)
创建command对象cmd
Dim cmd As New
连接到数据库
 DbConnect
设置cmd的ActiveConnection属性，指定其关联的数据库链接
 Set cmd.ActiveConnection = cnn
设置要执行的命令文本    
  = tmpSql
执行命令
 cmd.Execute
清空cmd对象
 Set cmd = noting
断开与数据库的连接
 Db_Disconnect
 
End Sub

执行数据库查询程函数
Public Function QueryExt(tmpSql As String) As ADODB.Recordset
创建recordset对象rst
Dim rst As New ADODB.Recordset
链接到数据库
Db_Connect
设置rst的ActiveConnection属性，指定与其关联的数据库连接
Set rst.ActiveConnection = cnn
设置游标类型
rst.CursorType = adOpenDynamic
设置锁定类型
rst.LockType = adLockOptimistic
打开记录集
rst.Open tmpSql
返回记录集
Set QueryExt = rst

End Function