vs怎么连接数据库

你有数据库吗？

连接你的数据库的位置，加他的 连接条件就可以拉下面是一个连接数据库的模块，大家可以使用它来连接SQL数据库，使用起来比ADO控件还简单：

代码如下：

Public rsNew As ADODB.Recordset

Public CnNew As ADODB.Connection

Public addFlag As Boolean

'连接数据库

Public Function OpenCn() As Boolean

Dim Mag As String

On Error GoTo strErrMag

Set CnNew = New ADODB.Connection

CnNew.ConnectionTimeout = 25

CnNew.Provider = "sqloledb"

CnNew.Properties("data source").value = "" 'SQL服务器的名

CnNew.Properties("initial catalog").value = "pubs"'库名

CnNew.Properties("integrated security").value = "SSPI"'登陆类型

'con.Properties("user id").value = "sa"

'con.Properties("password").value = "wwww"

CnNew.Open

OpenCn = True

addFlag = True

Exit Function

strErrMag:

Mag = "数据库末连接"

Call MsgBox(Mag, vbOKCancel, "错误:数据库连接")

addFlag = False

End

End Function

Public Sub Clocn()

'闭关数据库

On Error Resume Next

If CnNew.State <>adStateClosed Then CnNew.Close

Set CnNew = Nothing

End Sub

Public Function OpenRs(ByVal strSql As String) As Boolean

'连接数据库记录集

Dim Mag As String

Dim rpy As Boolean

On Error GoTo strErrMag

Set rsNew = New ADODB.Recordset

If addFlag = False Then rpy = OpenCn

With rsNew

.ActiveConnection = CnNew

.CursorLocation = adUseClient

.CursorType = adOpenKeyset

.LockType = adLockOptimistic

.Open strSql

End With

addFlag = True

OpenRs = True

Exit Function

strErrMag:

Mag = "数据库数据集末连接"

Call MsgBox(Mag, vbOKOnly, "错误:数据库连接")

OpenRs = False

End

End Function

Public Sub cloRs()

'闭关数据集

On Error Resume Next

If rsNew.State <>adStateClosed Then rsNew.Close

Set rsNew = Nothing

End Sub

private void Button1_Click(object sender,EventArgs e)

{

//获取用户输入的用户名和密码

var id=txt_id.text

var pwd=txt_pwd.text

var result=0//定义一个变量接受结果

var cmd="select count(*) from zhucedenglu where id=@id and password=@pwd" //sql语句

var constr="" //连接字符串自己写

//定义参数列表

var sqlparas=new SQLParameter[]{

new SQLParameter("@id",DBType.String){value=id},

new SQLParameter("@pwd",DBType.String){value=pwd}

}

//创建连接

using(var sqlcon=new SQLConnection(constr))

{

//创建命令对象

using(var sqlcmd=new SQLCommand(sqlcon,cmd))

{

sqlcmd.Parameters.AddRange(sqlparas) //添加参数

sqlcon.Open() //打开连接

result=sqlcmd.ExcuteScalar() //执行命令

}

}

if(result==1)

{

//TODO:登录成功

}

else

{

//TODO:登录失败

}

}

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