System.Data.OleDb Namespace OleDbCommand Class
Sends the CommandText to the Connection and builds an OleDbDataReader.
[ VB ]
Overloads Public Function ExecuteReader ( ) As OleDbDataReader
[ C# ]
public OleDbDataReader ExecuteReader ( );
[ C++ ]
public: OleDbDataReader* ExecuteReader ( );
[ JScript ]
public function ExecuteReader ( ) : OleDbDataReader;
An OleDbDataReader object.
| Exception Type |
Condition |
| InvalidOperationException |
Occurs when Cannot execute a command within a transaction context that differs from the context in which the connection was originally enlisted. |
When the CommandType property is set to StoredProcedure, the CommandText property should be set to the name of the stored procedure. The command executes this stored procedure when you call ExecuteReader.
While the OleDbDataReader is in use, the associated OleDbConnection is busy serving the OleDbDataReader. While in this state, no other operatons can be performed on the OleDbConnection other than closing it. This is the case until the Close method of the OleDbDataReader is called.
The following example demonstrates using this version of the ExecuteReader method.
protected void ExecuteReaderDemo ( ) {
// specify the data source
OleDbConnection myConn = new OleDbConnection (
"Provider=Microsoft.ACE.OLEDB.12.0; Data Source=" +
Server.MapPath ( "~/app_data/dbtutor.mdb" ) );
// define the command query
String query = "SELECT ProductName, ProductDescription FROM Products";
OleDbCommand myCommand = new OleDbCommand ( query, myConn );
// open the connection and instantiate a datareader
myConn.Open ( );
OleDbDataReader myReader = myCommand.ExecuteReader ( );
// display datareader contents into html table
// first open the table and set up the table headers
html += "<table cellspacing=1 class='data' width=90%>";
html += "<tr>";
html += "<th>Product Name</th>";
html += "<th>Description</th>";
html += "</tr>";
// loop thru the reader
while ( myReader.Read ( ) ) {
html += "<tr>";
html += "<td>" + myReader.GetString ( 0 ) + "</td>";
html += "<td>" + myReader.GetString ( 1 ) + "</td>";
html += "</tr>";
}
// close the table
html += "</table>";
// close the reader and the connection
myReader.Close ( );
myConn.Close ( );
}
</script>
protected sub ExecuteReaderDemo ( )
' specify the data source
dim myConn as new OleDbConnection ( & _
"Provider=Microsoft.ACE.OLEDB.12.0; Data Source=" & _
Server.MapPath ( "~/app_data/dbtutor.mdb" ) )
' define the command query
dim query as String = "SELECT ProductName, ProductDescription FROM Products"
dim myCommand as new OleDbCommand ( query, myConn )
' open the connection and instantiate a datareader
myConn.Open ( )
dim myReader as OleDbDataReader = myCommand.ExecuteReader ( )
' display datareader contents into html table
' first open the table and set up the table headers
html &= "<table cellspacing=1 class='data' width=90%>"
html &= "<tr>"
html &= "<th>Product Name</th>"
html &= "<th>Description</th>"
html &= "</tr>"
' loop thru the reader
while myReader.Read ( )
html &= "<tr>"
html &= "<td>" + myReader.GetString ( 0 ) + "</td>"
html &= "<td>" + myReader.GetString ( 1 ) + "</td>"
html &= "</tr>"
end while
' close the table
html &= "</table>"
' close the reader and the connection
myReader.Close ( )
myConn.Close ( )
end sub
</script> |
| |
C# |
VB |
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OleDbCommand Members OleDbCommand.ExecuteReader Overload List
