连接sql2008类，我这样写，对不对

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;using System.Data;
using System.Data.Common;
using System.Data.OleDb;
using System.Data.SqlClient;namespace Utility
{
    class Dl_DbHelpSql
    {
        public string connString{get;set;}
        
        /*--------------  初始化函数   ----------------------*/
        public Dl_DbHelpSql()
        {
            //this.connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=access地址;";
            //如果我想连接sql2008，怎么写？？
        }        public Dl_DbHelpSql(String conStr)
        {
            this.connString = conStr;
        }        
        
        
        /*----------------     非静态函数区     ---------------------*/        //带参数的插入、删除、更新语句，返回受影响的记录的个数
        public int ExecuteNoQuery(string SQL, OleDbParameter[] parameters)
        {
            using (OleDbConnection conn = new OleDbConnection(connString))
            {
                OleDbCommand cmd = new OleDbCommand(SQL, conn);
                if (parameters != null)
                {  cmd.Parameters.AddRange(parameters);   }                try
                {
                    cmd.Connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;                }
                catch (System.Exception e)
                {
                    throw e;
                }
                finally 
                {
                    conn.Close();
                    cmd.Dispose();
                }            }
        }

Answer 1

"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=access地址;uid=sa;pwd=123456";

Answer 2

你的数据库操作类都是Access的，要把所有的ole都改成sql，SQL不管是哪个版本的链接串都是一样的server=服务器;uid=sa;pwd=123456;database=数据库;

Answer 3

请认真阅读MSDN中下列链接的内容，这是一份完整的SqlConnection的说明：
http://msdn.microsoft.com/zh-cn/library/ms254504.aspx

Answer 4

这是我部分的类代码，其中这块肯定有问题，小弟菜鸟，求教！SqlConnection connectionString = new SqlConnection("server=localhost;database=gongnuan;uid=sa;pwd=sa");//改成数据库名以前数据库连接都是写在web.config里的，这回客户要求写在类里，不会了求教！using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;using System.Data;
using System.Data.Common;
using System.Data.OleDb;
using System.Data.SqlClient;namespace Utility
{
    class Dl_DbHelpSql
    {
        SqlConnection connectionString = new SqlConnection("server=localhost;database=gongnuan;uid=sa;pwd=sa");//改成数据库名
        public Dl_DbHelpSql()
        {            
        }        #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 = 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;
            }
            else
            {
                return true;
            }
        }
        /// <summary>
        /// 表是否存在
        /// </summary>
        /// <param name="TableName"></param>
        /// <returns></returns>
        public static bool TabExists(string TableName)
        {
            string strsql = "select count(*) from sysobjects where id = object_id(N'[" + TableName + "]') and OBJECTPROPERTY(id, N'IsUserTable') = 1";
            //string strsql = "SELECT count(*) FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[" + TableName + "]') AND type in (N'U')";
            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;
            }
            else
            {
                return true;
            }
        }
        public static bool Exists(string strSql, params SqlParameter[] cmdParms)
        {
            object obj = 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 e;
                    }
                }
            }
        }

Answer 5

SqlConnection conn = new SqlConnection("Data Source=实例名;Initial Catalog=数据库名;uid=用户名;pwd=密码");

Answer 6

去下个SQLHelper，连接MS SQL不是问题