DBHelper助手

DBHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.Collections;

namespace LineWork.DAL
{
public class DBHelper
{
//数据库连接字符串(web.config来配置)，多数据库可使用DbHelperSQLP来实现.
//public static string connectionString = ConfigurationManager.AppSettings["ConnectionString"];
private static string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

/// <summary>
///无参构造函数
/// </summary>
public DBHelper()
{
connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
}

#region 公用方法

#region 判断是否存在某表的某个字段
/// <summary>
/// 判断是否存在某表的某个字段
/// </summary>
/// <param name="tableName">表名称</param>
/// <param name="columnName">列名称</param>
/// <returns>是否存在</returns>
public static bool ColumnExists(string tableName, string columnName)
{
string sql = "select count(1) from syscolumns where [id]=object_id('" + tableName + "') and [name]='" + columnName + "'";
object res = GetSingle(sql);
if (res == null)
{
return false;
}
return Convert.ToInt32(res) > 0;
}