一个SqlHelper类

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;
using System.Collections;
using System.Data;
using System.Configuration;
using System.Web;
/// <summary>
/// SqlHelper 的摘要说明
/// </summary>
public class SqlHelper
{
    private static readonly string connectionString = ConfigurationManager.ConnectionStrings["DataBaseString"].ConnectionString;
    public SqlHelper()
    {
    }

    #region 公用方法
    public static int GetMaxID(string FieldName, string TableName)
    {
        string strsql = "select max(" + FieldName + ")+1 from " + TableName;
        object obj = SqlHelper.GetSingle(strsql);
        if (obj == null)
        {
            return 1;
        }
        else
        {
            return int.Parse(obj.ToString());
        }
    }

    public static bool Exists(string strSql)
    {
        object obj = SqlHelper.GetSingle(strSql);
        int cmdresult;
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
        {
            cmdresult = 0;
        }
        else
        {
            cmdresult = int.Parse(obj.ToString());
        }
        if (cmdresult == 0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    public static bool Exists(string strSql, params SqlParameter[] cmdParms)
    {
        object obj = SqlHelper.GetSingle(strSql, cmdParms);
        int cmdresult;
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
        {
            cmdresult = 0;
        }
        else
        {
            cmdresult = int.Parse(obj.ToString());
        }
        if (cmdresult == 0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }
    #endregion

    #region 执行简单SQL语句
    /// <summary>
    /// 执行SQL语句，返回影响的记录数
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString)
    {
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            using (SqlCommand cmd = new SqlCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    connection.Close();
                    throw new Exception(E.Message);
                }
            }
        }
    }

    /// <summary>

补充：软件开发 , C# ,