求教 怎样将ACCESS数据库连接的代码改写成SQL连接的代码

如题 代码如下 怎样将此段代码改成连接SQL数据库的代码
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.OleDb;
/// <summary>
/// dataOperate 的摘要说明
/// </summary>
public class dataOperate
{
public dataOperate()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
//添加数据或删除数据
public bool adlData(string sql)
{
OleDbConnection Odbc = createCon();
Odbc.Open();
OleDbCommand com = new OleDbCommand(sql, Odbc);
int i = Convert.ToInt32(com.ExecuteNonQuery());
Odbc.Close();
if (i > 0)
{
return true;
}
else
{
return false;
}
}
//查找数据
public int isData(string sql)
{
OleDbConnection Odbc =createCon();
Odbc.Open();
OleDbCommand com = new OleDbCommand(sql, Odbc);
int i = Convert.ToInt32(com.ExecuteScalar());
Odbc.Close();
return i;
}
//更新数据
public void updateData(string sql)
{
OleDbConnection Odbc =createCon();
Odbc.Open();
OleDbCommand com = new OleDbCommand(sql,Odbc);
com.ExecuteScalar();
Odbc.Close();
}
//查找并返回一条数据
public OleDbDataReader row(string sql)
{
OleDbConnection Odbc =createCon();
Odbc.Open();
OleDbCommand com = new OleDbCommand(sql, Odbc);
return com.ExecuteReader();
}
//查找并返回多条数据
public DataTable rows(string sql, string table)
{
DataSet ds;
OleDbConnection Odbc =createCon();
Odbc.Open();
OleDbDataAdapter oda = new OleDbDataAdapter(sql,Odbc);
ds = new DataSet();
oda.Fill(ds,table);
Odbc.Close();
return ds.Tables[table];
}
//创建数据库连接
public OleDbConnection createCon()
{
OleDbConnection odbc = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data source=|DataDirectory|db_study.mdb;");
return odbc;
}
}