ADO.NET之5-使用Command对象删除记录---ShinePans

源代码:

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

namespace SQLTest
{
class Program
{
static void Main(string[] args)
{
//连接数据库
string connection =
"server=潘尚\\SQLEXPRESS;database=db_test;Trusted_Connection=true";
SqlConnection sc = new SqlConnection(connection);
sc.ConnectionString = connection;
try
{
sc.Open(); //打开数据库连接
Console.WriteLine("已经打开数据库连接!");
string cmdtext = "DELETE FROM db_student WHERE student_name=@name";
SqlCommand cmd = new SqlCommand(cmdtext, sc);
cmd.Parameters.Add("@name", SqlDbType.VarChar).Value = "潘";
int i = cmd.ExecuteNonQuery();
if (i > 0) Console.WriteLine("删除记录成功!");
//////添加记录的代码//////
/* SqlCommand cmd = new SqlCommand();//创建SqlCommand对象
cmd.CommandType = CommandType.Text; //设置执行文本命令
cmd.Connection = sc; //设置对象属性
cmd.CommandText =
"INSERT INTO db_student(student_name,student_age,student_address,student_grade)VALUES(@name,@age,@address,@grade)";
//添加参数并为参数赋值
cmd.Parameters.Add("@name", SqlDbType.VarChar, 10).Value = "潘";
cmd.Parameters.Add("@age", SqlDbType.Int).Value = 19;
cmd.Parameters.Add("@address", SqlDbType.VarChar).Value = "武汉";
cmd.Parameters.Add("@grade", SqlDbType.Int).Value = 100;
int i = cmd.ExecuteNonQuery(); //执行数据库添加记录命令
if (i > 0) Console.WriteLine("添加记录成功"); //控制台输出添加记录
* ////添加记录的代码///////*/
}
catch (Exception ex)
{
Console.WriteLine("打开数据库错误:{0}", ex.Message);
}
finally
{
sc.Close();
Console.WriteLine("数据库连接已关闭!");
}
System.Console.ReadLine();
}
}
}


删除执行:



删除后的状态:



总结:注意cmdtext的正确性