System.Data.SqlClient Namespace SqlCommand Class
Sends the CommandText to the Connection and builds an SqlDataReader.
[ VB ]
Overloads Public Function ExecuteReader ( ) As SqlDataReader
[ C# ]
public SqlDataReader ExecuteReader ( );
[ C++ ]
public: SqlDataReader* ExecuteReader ( );
[ JScript ]
public function ExecuteReader ( ) : SqlDataReader;
An SqlDataReader 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 SqlDataReader is in use, the associated SqlConnection is busy serving the SqlDataReader. While in this state, no other operatons can be performed on the SqlConnection other than closing it. This is the case until the Close method of the SqlDataReader is called.
The following example demonstrates using this version of the ExecuteReader method.
protected void ExecuteReaderDemo ( ) {
// specify the data source
SqlConnection myConn = new SqlConnection (
"server=localhost; trusted_connection=yes; database=northwind" );
// define the command query
String query = "SELECT CustomerID, CompanyName FROM Customers";
SqlCommand myCommand = new SqlCommand ( query, myConn );
// open the connection and instantiate a datareader
myConn.Open ( );
SqlDataReader 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>Customer ID</th>";
html += "<th>Company Name</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 SqlConnection ( & _
"server=localhost; trusted_connection=yes; database=northwind" )
' define the command query
dim query as String = "SELECT CustomerID, CompanyName FROM Customers"
dim myCommand as new SqlCommand ( query, myConn )
' open the connection and instantiate a datareader
myConn.Open ( )
dim myReader as SqlDataReader = 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>Customer ID</th>"
html &= "<th>Company Name</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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SqlCommand Members SqlCommand.ExecuteReader Overload List
