Visual Studio中访问SQL数据库的操作结果 ExecuteNonQuery执行一个SqlCommand返回操作影响的行数，这个多半是判断操作是否成功的

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace UseSqlCm
{
    class Program
    {
        static void Main(string[] args)
        {
            string strCon = "Data Source=.;Initial Catalog=Northwind;uid=sa;pwd=Daniel";
            using (SqlConnection con = new SqlConnection(strCon))
            {
                using (SqlCommand cmd = con.CreateCommand())
                {
                    //string strSql = "select count(*) from Customers";
                    //cmd.CommandText = strSql;
                    //con.Open();
                    //int intCount = Int32.Parse(cmd.ExecuteScalar().ToString()); //ExecuteScaler();
                    //Console.WriteLine(intCount);

                    //cmd.CommandText = "select * from Customers";
                    //string strS = cmd.ExecuteScalar().ToString(); //ExecuteScalar() 返回结果集的首行首列
                    //Console.WriteLine(strS); //ALFKI 返回结果集的首行首列
                    string ins = "insert into Categories(CategoryName) values ('CateNameTest')"; //插入
                    string upt = "update Categories set CategoryName = 'aa' where CategoryID=9"; //修改
                    string del = "deleted from Categories where CategoryID=9";                //删除ID=9的记录

                    con.Open();
                    cmd.CommandText = ins;
                    int intResult = cmd.ExecuteNonQuery(); 
                    //ExecuteNonQuery执行一个SqlCommand返回操作影响的行数，这个多半是判断操作是否成功的，
                    //例如插入删除和更新操作，如果影响行数为0的话，则证明操作是不成功的。大于0证明操作成功
                    if (intResult > 0)
                    {
                        Console.WriteLine("成功插入" + intResult + "条记录");
                    }
                    else
                    {
                        Console.WriteLine("插入失败！");
                    }


                }
            }
            Console.ReadKey();                        
        }
    }
}