基于SQLServer的数据访问基础类

/// <summary>
/// 数据访问基础类(基于SQLServer)
/// Copyright (C) 2008-2009 小笨蛋
/// </summary>
public class DbHelperSQL
{
//数据库连接字符串(web.config来配置)
public static string connectionString = PubConstant.ConnectionString;
public DbHelperSQL()
{
}
#region 公用方法
/// <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;
}
public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = DbHelperSQL.GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
public static bool Exists(string strSql)
{
object obj = 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;
}