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();                                }    }}