c# - Webservice convert from string to System.Data.SqlClient.SqlCommand

Question

I'm trying to get an list of items from some table of SQL Server. I'm doing it with Visual Studio 2010.

That's my code:

static string filter = "25";

DataSet Datos = new DataSet();
SqlConnection MyConnection = default(SqlConnection);
SqlDataAdapter MyDataAdapter = default(SqlDataAdapter);
MyConnection = new SqlConnection("Initial Catalog=MyDataBase;Data Source=MyServer;Integrated Security=false;User ID=SQLUser;Password=SQLPass;");
MyDataAdapter = new SqlDataAdapter("SELECT Comment FROM MyTable WHERE [No_] = "+filter+" , MyConnection);
MyDataAdapter.SelectCommand.CommandType = CommandType.Text;
MyDataAdapter.Fill(Datos);
MyDataAdapter.Dispose();
MyConnection.Close();

I'm getting this error:

Argument 1: cannot convert from 'string' to 'System.Data.SqlClient.SqlCommand'

On this line:

MyDataAdapter = new SqlDataAdapter("SELECT Comment FROM MyTable WHERE [No_] = "+filter+" , MyConnection);

So, how can I put the string into my SqlConnection?

Thanks in advance.

Answer 1

这对我有用：

string filter = "10";

DataSet Datos = new DataSet();
string connectionString = "<your connection string here>";
string selectCommand = 
  "SELECT * FROM myTable WHERE Id = " + filter;
using (var MyConnection = new SqlConnection(connectionString))
using (var MyDataAdapter = new SqlDataAdapter(selectCommand, MyConnection))
{
   MyDataAdapter.SelectCommand.CommandType = CommandType.Text;
   MyDataAdapter.Fill(Datos);
}

这基本上是您的代码，使用 using 语法。如果您仍然有问题，请尝试并发布。祝你好运！