Question

无法将类型“System.Data.SqlClient.SqlConnection”隐式转换为“string

以下为实现登录功能的代码，请问错误在哪里？ protected void Button2_Click(object sender, EventArgs e) { string conn = new SqlConnection("Data Source=(local)\\SQLEXPRESS;Integrated Security=true;database=bj1"); string strCmd="select count(*) from dbo.Table_1 where(username like '"+TextBox1.Text+"'and code like '"+TextBox2.Text+"')"; SqlConnection myConnection=new SqlConnection(); myConnection.ConnectionString=conn; SqlCommand myCommand=new SqlCommand(strCmd,myConnection); myCommand.Connection.Open(); //检索出的用户数 int flag=(int)myCommand.ExecuteScalar(); myCommand.Connection.Close(); myConnection.Close(); Response.Write("<script>alert('登陆成功')</script>"); } 请问错在哪里？谢谢

Answer 1

string conn = new SqlConnection("Data Source=(local)\\SQLEXPRESS;Integrated Security=true;database=bj1"); 你new的是SqlConnection类型，不能用string接受，改为SqlConnection conn = new SqlConnection("Data Source=(local)\\SQLEXPRESS;Integrated Security=true;database=bj1");

Answer 2

string conn = new SqlConnection("Data Source=(local)\\SQLEXPRESS;问题出现在这里。。

Answer 3

SqlConnection myConnection=new SqlConnection ();
myConnection.ConnectionString = "Data Source=ZWZX008\\SQL2005; Initial Catalog=northwind;User ID=Sa;Password=123456";
myConnection.Open();
SqlCommand myCommand = new SqlCommand(myConnection);
myCommand.CommandText = "Select * from Customers";
SqlDataReader myReader;
myReader = myCommand.ExecuteReader();