本文轉自： http://xyz610561646.web64.hezuwang.com/html/200712/85/13073.htm
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Text;
namespace ChinaSite.classes
{
??? public class DbAccess
??? {
??????? SqlConnection conn = null;
??????? SqlCommand cmd = null;
??????? public DbAccess()
??????? {
??????????? //
??????????? // TODO: 在此處添加構造函數邏輯
??????????? //
??????????? conn = new SqlConnection();
??????????? //conn.ConnectionString = "initial catalog=pubs;data source=.;user id=sa;password=";
??????????? //conn.ConnectionString = Convert.ToString(System.Configuration.ConfigurationSettings.AppSettings["datasource"]);
??????????? conn.ConnectionString = Convert.ToString(System.Configuration.ConfigurationManager.AppSettings["datasource"]);
??????????? cmd = new SqlCommand();
??????????? cmd.Connection = conn;
??????? }
??????? /// <summary>
??????? /// 獲取數據根據sql語句?
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <returns></returns>
??????? public DataTable GetTable(string sql)
??????? {
??????????? DataSet ds = new DataSet();
??????????? try
??????????? {
??????????????? cmd.CommandText = sql;
??????????????? SqlDataAdapter da = new SqlDataAdapter();
??????????????? da.SelectCommand = cmd;
??????????????? da.Fill(ds);
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return null;
??????????? }
??????????? return ds.Tables[0] ?? new DataTable();
??????? }
??????? /// <summary>
??????? /// 獲取數據根據sql語句 帶參數 的?
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <param name="pas"></param>
??????? /// <returns></returns>
??????? public DataTable GetTable(string sql, params SqlParameter[] pas)
??????? {
??????????? DataSet ds = new DataSet();
??????????? try
??????????? {
??????????????? cmd.CommandText = sql;
??????????????? SqlDataAdapter da = new SqlDataAdapter();
??????????????? da.SelectCommand = cmd;
??????????????? cmd.Parameters.Clear();
??????????????? foreach (SqlParameter temppa in pas)
??????????????? {
??????????????????? cmd.Parameters.Add(temppa);
??????????????? }

??????????????? da.Fill(ds);
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return null;
??????????? }
??????????? return ds.Tables[0] ?? new DataTable();
??????? }
??????? /// <summary>
??????? /// 根據sql語句返回跟新狀態
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <returns></returns>
??????? public bool GetState(string sql)
??????? {
??????????? bool succ = false;
??????????? try
??????????? {
??????????????? cmd.CommandText = sql;
??????????????? conn.Open();
??????????????? succ = cmd.ExecuteNonQuery() > 0 ? (true) : (false);
??????????????? conn.Close();
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return false;
??????????? }
??????????? return succ;
??????? }
??????? /// <summary>
??????? /// 根據sql語句返回跟新狀態帶參數的?
??????? /// </summary>
??????? /// <param name="sql">sql語句</param>
??????? /// <param name="pas">參數的集合</param>
??????? /// <returns></returns>
??????? public bool GetState(string sql, params SqlParameter[] pas)
??????? {
??????????? bool succ = false;
??????????? try
??????????? {
??????????????? cmd.CommandText = sql;
??????????????? cmd.Parameters.Clear();
??????????????? foreach (SqlParameter temppa in pas)
??????????????? {
??????????????????? cmd.Parameters.Add(temppa);
??????????????? }
??????????????? conn.Open();
??????????????? succ = cmd.ExecuteNonQuery() > 0 ? (true) : (false);
??????????????? conn.Close();
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return false;
??????????? }
??????????? return succ;
??????? }
??????? /// <summary>
??????? /// 根據sql語句返回第一個單元格的數據
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <returns></returns>
??????? public string GetOne(string sql)
??????? {
??????????? string res = "";
??????????? try
??????????? {
??????????????? cmd.CommandText = sql;
??????????????? conn.Open();
??????????????? res = cmd.ExecuteScalar() == null ? ("") : (Convert.ToString(cmd.ExecuteScalar()));
??????????????? conn.Close();
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return null;
??????????? }
??????????? return res;
??????? }
??????? /// <summary>
??????? ///? 根據sql語句返回第一個單元格的數據帶參數的?
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <param name="pas"></param>
??????? /// <returns></returns>
??????? public string GetOne(string sql, params SqlParameter[] pas)
??????? {
??????????? string res = "";
??????????? try
??????????? {
??????????????? cmd.CommandText = sql;
??????????????? cmd.Parameters.Clear();
??????????????? foreach (SqlParameter temppa in pas)
??????????????? {
??????????????????? cmd.Parameters.Add(temppa);
??????????????? }
??????????????? conn.Open();
??????????????? res = cmd.ExecuteScalar() == null ? ("") : (Convert.ToString(cmd.ExecuteScalar()));
??????????????? conn.Close();
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return null;
??????????? }
??????????? return res;
??????? }
??????? /// <summary>
??????? /// 返回數據的DataReader
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <returns></returns>
??????? public SqlDataReader GetDataReader(string sql)
??????? {
??????????? SqlDataReader dr = null;
??????????? try
??????????? {
??????????????? conn.Open();
??????????????? cmd.CommandText = sql;
??????????????? dr = cmd.ExecuteReader();
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return null;
??????????? }
??????????? return dr;
??????? }
??????? /// <summary>
??????? /// 返回數據的DataReader帶參數的?
??????? /// </summary>
??????? /// <param name="sql"></param>
??????? /// <param name="pas"></param>
??????? /// <returns></returns>
??????? public SqlDataReader GetDataReader(string sql, params SqlParameter[] pas)
??????? {
??????????? SqlDataReader dr = null;
??????????? try
??????????? {
??????????????? conn.Open();
??????????????? cmd.Parameters.Clear();
??????????????? foreach (SqlParameter temppa in pas)
??????????????? {
??????????????????? cmd.Parameters.Add(temppa);
??????????????? }
??????????????? cmd.CommandText = sql;
??????????????? dr = cmd.ExecuteReader();
??????????? }
??????????? catch (Exception ex)
??????????? {
??????????????? this.ShowError(ex.Message);
??????????????? return null;
??????????? }
??????????? return dr;
??????? }
??????? /// <summary>
??????? /// 打開連接
??????? /// </summary>
??????? public void OpenConn()
??????? {
??????????? if (conn.State != ConnectionState.Open)
??????????? {
??????????????? try
??????????????? {
??????????????????? conn.Open();
??????????????? }
??????????????? catch (Exception ex)
??????????????? {
??????????????????? this.ShowError(ex.Message);
??????????????????? return;
??????????????? }
??????????? }
??????? }
??????? /// <summary>
??????? /// 關閉連接
??????? /// </summary>
??????? public void CloseConn()
??????? {
??????????? if (conn.State != ConnectionState.Closed)
??????????? {
??????????????? try
??????????????? {
??????????????????? conn.Close();
??????????????????? cmd = null;
??????????????????? conn = null;
??????????????? }
??????????????? catch (Exception ex)
??????????????? {
??????????????????? this.ShowError(ex.Message);
??????????????????? return;
??????????????? }
??????????? }
??????? }
??????? /// <summary>
??????? /// 彈出錯誤的信息?
??????? /// </summary>
??????? /// <param name="err"></param>
??????? public void ShowError(string err)
??????? {
??????????? System.Web.HttpContext.Current.Response.Write(Script(err, ""));
??????? }
??????? /// <summary>
??????? /// 顯示信息?
??????? /// </summary>
??????? /// <param name="err"></param>
??????? public void ShowMessage(string mes, string loc)
??????? {
??????????? System.Web.HttpContext.Current.Response.Write(Script(mes, loc));
??????? }
??????? /// <summary>
??????? /// javascript腳本
??????? /// </summary>
??????? /// <param name="mess"></param>
??????? /// <param name="loc"></param>
??????? /// <returns></returns>
??????? public string Script(string mess, string loc)
??????? {
??????????? StringBuilder sb = new StringBuilder();
??????????? sb.Append("<script language='javascript'>");
??????????? sb.Append("alter('");
??????????? sb.Append(mess);
??????????? sb.Append("');");
??????????? sb.Append(loc);
??????????? sb.Append("</script>");
??????????? return sb.ToString();
??????? }
??? }
}

本文來自: 天空618(www.sky618.com) 詳細出處參考：http://xyz610561646.web64.hezuwang.com/html/200712/85/13073.htm

c# 數據庫的 sql 參數封裝類的編寫