Tài liệu Creating a Sqldatareader Objec ppt

Creating a Sg/DataReader Object You can create a DataReader object only by calling the ExecuteReader method of a Command object.. Command objects were covered in the previous chapter.. F

Creating a Sg/DataReader Object

You can create a DataReader object only by calling the ExecuteReader() method of a Command object Command objects were covered in the previous chapter For example, the following code creates the required objects and executes a SELECT statement that retrieves the top five rows from the Products table of the SQL Server Northwind

database, storing the returned rows in a SqlDataReader object:

SqlConnection mySqlConnection =

new SqlConnection(

"server=localhost;database=Northwind;uid=sa;pwd=sa"

);

SqlCommand mySqlCommand = mySqlConnection.CreateCommand();

mySqlCommand.CommandText =

"SELECT TOP 5 ProductID, ProductName, UnitPrice, " +

"UnitsInStock, Discontinued " +

"FROM Products " +

"ORDER BY ProductID";

mySqlConnecfion.Open();

SqlDataReader productsSalDataReader =

mySqlCommand.ExecuteReader();

Notice that the SqlDataReader object returned by the ExecuteReader() method is stored

in the productsSq]DataReader object You'll see how to use productsSqlDataReader in the following section