Bind Results in C# using SQL prepared statements

问题

Using this:

SqlConnection myConnection = new SqlConnection("Data Source=.\\SERVER;Initial Catalog=DB;Integrated Security=True;TrustServerCertificate=True;User Instance=False");
myConnection.Open();

SqlCommand myCommand = new SqlCommand("SELECT BusinessName FROM Businessess WHERE BusinessID = @Param2", myConnection);

SqlParameter myParam2 = new SqlParameter("@Param2", SqlDbType.Int, 4);
myParam2.Value = 1;
myCommand.Parameters.Add(myParam2);

MessageBox.Show(myCommand); //How do I bind results to show as string?

How do I bind the results of a prepared statement to a variable so that I may manipulate them?

回答1:

Try like this:

using (SqlConnection myConnection = new SqlConnection("Data Source=.\\SERVER;Initial Catalog=DB;Integrated Security=True;TrustServerCertificate=True;User Instance=False"))
using (SqlCommand myCommand = myConnection.CreateCommand())
{
    myConnection.Open();
    myCommand.CommandText = "SELECT BusinessName FROM Businessess WHERE BusinessID = @Param2";
    myCommand.Parameters.AddWithValue("@Param2", myParam2);
    using (SqlDataReader reader = myCommand.ExecuteReader())
    {
        if (reader.Read())
        {
            string businessName = reader.GetString(reader.GetOrdinal("BusinessName"));
            MessageBox.Show(businessName);
        }
        else
        {
            MessageBox.Show(string.Format("Sorry, no business found with id = {0}", myParam2));
        }
    }
}

Things to notice:

disposable resources are wrapped in using statements to ensure proper disposal even in case of exceptions
simplification of the parameter passed to the sql command
call the ExecuteReader on the command in order to retrieve an object allowing you to read the returned resultset.

来源：https://stackoverflow.com/questions/9241238/bind-results-in-c-sharp-using-sql-prepared-statements

标签

sql

prepared-statement