DBHelper.cs
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Data.SqlClient; using System.Data; namespace ConsoleApp1 { class DBHelper { public static string strConn = "Server=127.0.0.1;uid=sa;pwd=wu111111;Database=test"; /// <summary> /// 增、删、改通用方法 /// </summary> /// <param name="Sql">SQL 语句</param> /// <param name="paras">可选参数</param> /// <returns></returns> public static int ExecuteNonQuery(string Sql, params SqlParameter[] paras) { int result = 0; //using 自动关闭资源,自带异常处理机制 using (SqlConnection conn = new SqlConnection(strConn)) { conn.Open();//打开连接 SqlCommand command = new SqlCommand(Sql, conn);//执行命令 command.Parameters.AddRange(paras);//加入参数 result = command.ExecuteNonQuery(); //执行 } return result; } /// <summary> /// 查询单行当列 /// </summary> /// <param name="Sql">SQL 语句</param> /// <param name="paras">可选参数</param> /// <returns></returns> public static Object ExecuteScalar(string Sql, params SqlParameter[] paras) { Object result; //using 自动关闭资源,自带异常处理机制 using (SqlConnection conn = new SqlConnection(strConn)) { conn.Open();//打开连接 SqlCommand command = new SqlCommand(Sql, conn);//执行命令 command.Parameters.AddRange(paras);//加入参数 result = command.ExecuteScalar(); //执行 } return result; } /// <summary> /// 执行返回游标方式结果集 /// </summary> /// <param name="Sql"></param> /// <param name="paras"></param> /// <returns></returns> public static Object ExecuteReader(string Sql, params SqlParameter[] paras) { //using 自动关闭资源,自带异常处理机制 SqlConnection conn = new SqlConnection(strConn); conn.Open();//打开连接 SqlCommand command = new SqlCommand(Sql, conn);//执行命令 command.Parameters.AddRange(paras);//加入参数 SqlDataReader result = command.ExecuteReader(CommandBehavior.CloseConnection); //执行 return result; } /// <summary> /// 执行返回临时表 /// </summary> /// <param name="Sql"></param> /// <param name="paras"></param> /// <returns></returns> public static DataTable GetDataTable(string Sql, params SqlParameter[] paras) { DataTable dt = new DataTable(); using (SqlConnection conn = new SqlConnection(strConn)) { SqlCommand command = new SqlCommand(Sql, conn); command.Parameters.AddRange(paras);//添加参数 //创建诗句适配器 SqlDataAdapter adapter = new SqlDataAdapter(command); //填充 adapter.Fill(dt); return dt; } } } }
使用方法:
int id = 1; string psw = "admin88811"; //防SQL注入 SqlParameter[] para = new SqlParameter[] { new SqlParameter("@id",id), new SqlParameter("@psw",psw) }; Console.WriteLine("连接数据库成功"); //步骤3: 创建执行脚本的对象 string sql = "SELECT name from tbuser where id=@id and psw=@psw"; string result = (string)DBHelper.ExecuteScalar(sql, para); Console.WriteLine(result);
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