C#基础-连接Access与SQL Server

1.连接Access数据库

string strConnection = "Provider=Microsoft.Ace.OleDb.12.0; Data Source=" + Server.MapPath("~\App_Data\db1.accdb");

OleDbConnection cnn;
OleDbCommand cmd;
OleDbDataReader datar;

string str_sql = "select * from T_product where ID=0;";
cnn = new OleDbConnection(strConnection);
cnn.Open();
cmd = new OleDbCommand(str_sql, cnn);
datar = cmd.ExecuteReader();

while (datar.Read())
{
     //do something
}

cnn.Close();

2.连接SQL Server数据库
首先在Webconfig里添加连接字段

<connectionStrings>
    <add name="ApplicationServices"
         connectionString="Server=(local);Integrated Security=SSPI;database=TestServer;uid=***;pwd=***" providerName="System.Data.SqlClient"/>
  </connectionStrings>

然后

string setting = "ApplicationServices";
var connString = System.Web.Configuration.WebConfigurationManager.ConnectionStrings[setting];

            SqlConnection conn = new SqlConnection(connString.ConnectionString);
            SqlCommand cmd;
            SqlDataReader datar;
            string str_sql = "select * from T_category;";
            conn.Open();
            cmd = new SqlCommand(str_sql, conn);
            datar = cmd.ExecuteReader();
            while (datar.Read())

            {
                  // do something
            }
            conn.Close();