SqlCeDataReader.Read Method

Article
10/22/2009

Advances SqlCeDataReader to the next record.

Namespace: System.Data.SqlServerCe
Assembly: System.Data.SqlServerCe (in system.data.sqlserverce.dll)

Syntax

'Declaration
Public Overrides Function Read As Boolean

public override bool Read ()

public:
virtual bool Read () override

public boolean Read ()

public override function Read () : boolean

Return Value

true if there are more rows; otherwise, false.

Remarks

The default position of the SqlCeDataReader is prior to the first record. To begin accessing any data, you must call Read. The default position of the SqlCeResultSet is the first record. Calling SqlCeResultSet.Read method immediately after creating the SqlCeResultSet will move the cursor to the second record. For SqlCeDataReader.Read, the behaviour is different from that of SqlCeResultSet.Read.

While SqlCeDataReader is in use, the associated SqlCeConnection is busy serving it until you call Close.

Example

The following example creates a SqlCeConnection, a SqlCeCommand, and a SqlCeDataReader. The example reads through the data and writes it out to the console. Finally, the example closes the SqlCeDataReader, then the SqlCeConnection.

Dim conn As SqlCeConnection = Nothing
Dim cmd As SqlCeCommand = Nothing
Dim rdr As SqlCeDataReader = Nothing

Try
    ' Open the connection and create a SQL command
    '
    conn = New SqlCeConnection("Data Source = AdventureWorks.sdf")
    conn.Open()
    
    cmd = New SqlCeCommand("SELECT * FROM DimEmployee", conn)
    
    rdr = cmd.ExecuteReader()
    
    ' Iterate through the results
    '
    While rdr.Read()
        Dim employeeID As Integer = rdr.GetInt32(0) ' or: rdr["EmployeeKey"];
        Dim lastName As String = rdr.GetString(5) ' or: rdr["FirstName"];
    End While
    
    ' Always dispose data readers and commands as soon as practicable
    '
    rdr.Close()
    cmd.Dispose()
Finally
    ' Close the connection when no longer needed
    '
    conn.Close()
End Try

SqlCeConnection conn = null;
SqlCeCommand cmd = null;
SqlCeDataReader rdr = null;

try
{
    // Open the connection and create a SQL command
    //
    conn = new SqlCeConnection("Data Source = AdventureWorks.sdf");
    conn.Open();

    cmd = new SqlCeCommand("SELECT * FROM DimEmployee", conn);

    rdr = cmd.ExecuteReader();

    // Iterate through the results
    //
    while (rdr.Read())
    {
        int employeeID = rdr.GetInt32(0);   // or: rdr["EmployeeKey"];
        string lastName = rdr.GetString(5); // or: rdr["FirstName"];
    }

    // Always dispose data readers and commands as soon as practicable
    //
    rdr.Close();
    cmd.Dispose();
}
finally
{
    // Close the connection when no longer needed
    //
    conn.Close();
}

Thread Safety

Any public static (Shared in Microsoft Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Development Platforms

Windows Vista, Windows Mobile 5.0, Windows XP Professional with Service Pack 2 (SP2), Windows Server 2003, Windows Mobile 2003 for Pocket PC, Windows CE 5.0
Version Information
.NET Framework and NET Compact Framework
Supported in 3.5
.NET Framework
Supported in 3.0
.NET Compact Framework and .Net Framework
Supported in 2.0