下面的代码，为什么第1个不需要手动关闭数据库连接，第2个却需要？第2个不手动关闭连接行吗？
下面的代码，为什么第1个不需要手动关闭数据库连接，第2个却需要？第2个不手动关闭连接行吗？即把


1).
System.Data.IDataReader dataReader = dbCommand.ExecuteReader

(System.Data.CommandBehavior.CloseConnection);
改成
System.Data.IDataReader dataReader = dbCommand.ExecuteReader();


System.Data.DataSet GetProductsDataSet() {
string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Ole DB Services=-4; Data

Source=C:\\BEGASPNET11\\ " +
"data\\Northwind.mdb ";
System.Data.IDbConnection dbConnection = new System.Data.OleDb.OleDbConnection

(connectionString);

string queryString = "SELECT [Products].[ProductName], [Categories].[CategoryName] FROM

[Products], [Ca " +
"tegories] WHERE ([Categories].[CategoryID] = [Products].[CategoryID]) ";
System.Data.IDbCommand dbCommand = new System.Data.OleDb.OleDbCommand();
dbCommand.CommandText = queryString;
dbCommand.Connection = dbConnection;

System.Data.IDbDataAdapter dataAdapter = new System.Data.OleDb.OleDbDataAdapter();
dataAdapter.SelectCommand = dbCommand;
System.Data.DataSet dataSet = new System.Data.DataSet();
dataAdapter.Fill(dataSet);

return dataSet;
}


2).

System.Data.IDataReader GetProductsReader() {
string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Ole DB Services=-4; Data

Source=C:\\BEGASPNET11\\ " +
"data\\Northwind.mdb ";
System.Data.IDbConnection dbConnection = new System.Data.OleDb.OleDbConnection

(connectionString);

string queryString = "SELECT [Products].[ProductName], [Products].[QuantityPerUnit],

[Products].[UnitPr " +
"ice], [Products].[UnitsInStock] FROM [Products] ";
System.Data.IDbCommand dbCommand = new System.Data.OleDb.OleDbCommand();
dbCommand.CommandText = queryString;
dbCommand.Connection = dbConnection;

dbConnection.Open();
System.Data.IDataReader dataReader = dbCommand.ExecuteReader

(System.Data.CommandBehavior.CloseConnection);

return dataReader;
}
void Page_Load(Object sender, EventArgs e) {
DataGrid1.DataSource = GetProductsReader();
DataGrid1.DataBind();
}

[解决办法]
友情UP
[解决办法]
只要是datareader就要,dataset可以不用
[解决办法]
只要你手动开了就得手动关