.net中訪問數據庫的兩中方法
第一種是通過SqlHelper幫助類來訪問數據庫,
使用的是ADO.net技術。
using System.Data;
using System.Data.SqlClient;
public static class SqlHelper
{
/// <summary>
/// 數據庫連接字符串
/// </summary>
private static string ConnectionString = "Data Source=.;Initial Catalog=MyQQ;User ID=sa;Pwd=sa";
/// <summary>
/// 返回受影響的行數
/// </summary>
public static int ExecuteNonQuery(string sql)
{
using (SqlConnection con = new SqlConnection(ConnectionString))
{
SqlCommand cmd = new SqlCommand(sql, con);
try
{
con.Open();
return cmd.ExecuteNonQuery();
}
catch (SqlException)
{
throw;
}
}
}
/// <summary>
/// 返回DataSet
/// </summary>
public static DataSet ExecuteDataSet(string sql)
{
using (SqlConnection con = new SqlConnection(ConnectionString))
{
SqlDataAdapter adp = new SqlDataAdapter(sql, con);
DataSet ds = new DataSet();
try
{
adp.Fill(ds);
return ds;
}
catch (SqlException)
{
throw;
}
}
}
/// <summary>
/// 返回DataTable
/// </summary>
public static DataTable ExecuteDataTable(string sql)
{
return SqlHelper.ExecuteDataSet(sql).Tables[0];
}
/// <summary>
/// 返回單一值(第一行第一列)
/// </summary>
public static object ExecuteScalar(string sql)
{
using (SqlConnection con = new SqlConnection(ConnectionString))
{
SqlCommand cmd = new SqlCommand(sql, con);
try
{
con.Open();
return cmd.ExecuteScalar();
}
catch (SqlException)
{
throw;
}
}
}
上面是一個簡單的幫助類
通過使用
SqlConnection
SqlCommand
SqlDataAdapter
三個對象來實現