SqlCeResultSet.ReadAbsolute Method

Moves the reader to a specific record in the ResultSet.

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

Syntax

'Declaration
Public Function ReadAbsolute ( _
    position As Integer _
) As Boolean
'Usage
Dim instance As SqlCeResultSet
Dim position As Integer
Dim returnValue As Boolean

returnValue = instance.ReadAbsolute(position)

public bool ReadAbsolute (
    int position
)

public:
bool ReadAbsolute (
    int position
)

public boolean ReadAbsolute (
    int position
)

public function ReadAbsolute (
    position : int
) : boolean

Not applicable.

Parameters

• position
  The position to which to move the reader.

Return Value

True if the operation succeeded; otherwise, false.

Remarks

ReadAbsolute is 0-based; calling ReadAbsolute(0) will return the first row of the ResultSet.

This method reads the value of the row based on the row position saved by a bookmark. For example, suppose you have a table with 10 rows, and you open two ResultSets: rs1 and rs2. You call ReadAbsolue(5) on rs1 and change the value of this row to -1. The row's position has now changed to the first position in the list of rows, and row 4 is in the 5th position. However, if you now call ReadAbsolute(5) on rs2, a value of -1 is returned. ResultSet rs2 maintains a bookmark to the original 5th row and continues to read that row, despite its position changing.

If you pass a positive integer to this function, the reader is moved from the first record forward the specified number of records. If you pass a negative integer to this function, the reader is moved from the last record back the specified number of records.

Example

The following example creates a ResultSet object and then calls several methods, including ReadAbsolute.

Dim conn As SqlCeConnection = Nothing

Try
    File.Delete("Test.sdf")

    Dim engine As New SqlCeEngine("Data Source = Test.sdf")
    engine.CreateDatabase()

    conn = New SqlCeConnection("Data Source = Test.sdf")
    conn.Open()

    Dim cmd As SqlCeCommand = conn.CreateCommand()
    cmd.CommandText = "CREATE TABLE myTable (col1 INT)"
    cmd.ExecuteNonQuery()

    cmd.CommandText = "SELECT * FROM myTable"

    Dim rs As SqlCeResultSet = cmd.ExecuteResultSet(ResultSetOptions.Updatable Or ResultSetOptions.Scrollable)

    Dim rec As SqlCeUpdatableRecord = rs.CreateRecord()

    ' Insert 10 records
    '
    Dim i As Integer
    For i = 0 To 9
        rec.SetInt32(0, i)
        rs.Insert(rec)
    Next i

    ' Scroll through the results
    '
    If True = rs.ReadFirst() Then
        MessageBox.Show("col1 = " & rs.GetInt32(0)) 'ordinal
    End If

    If True = rs.ReadRelative(5) Then
        MessageBox.Show("col1 = " & rs.GetInt32(0)) 'ordinal
    End If

    If True = rs.ReadLast() Then
        MessageBox.Show("col1 = " & rs.GetInt32(0)) 'ordinal
    End If

    If True = rs.ReadPrevious() Then
        MessageBox.Show("col1 = " & rs.GetInt32(0)) 'ordinal
    End If

    If True = rs.ReadAbsolute(5) Then
        MessageBox.Show("col1 = " & rs.GetInt32(0)) 'ordinal
    End If
Catch e As Exception
    MessageBox.Show(e.Message)
Finally
    conn.Close()
End Try

SqlCeConnection conn = null;

try
{
    File.Delete("Test.sdf");

    SqlCeEngine engine = new SqlCeEngine("Data Source = Test.sdf");
    engine.CreateDatabase();

    conn = new SqlCeConnection("Data Source = Test.sdf");
    conn.Open();

    SqlCeCommand cmd = conn.CreateCommand();
    cmd.CommandText = "CREATE TABLE myTable (col1 INT)";
    cmd.ExecuteNonQuery();

    cmd.CommandText = "SELECT * FROM myTable";

    SqlCeResultSet rs = cmd.ExecuteResultSet(ResultSetOptions.Updatable | 
        ResultSetOptions.Scrollable);

    SqlCeUpdatableRecord rec = rs.CreateRecord();

    // Insert 10 records
    //
    for (int i = 0; i < 10; i++)
    {
        rec.SetInt32(0, i);
        rs.Insert(rec);
    }

    // Scroll through the results
    //
    if (true == rs.ReadFirst())
    {
        MessageBox.Show("col1 = " + rs.GetInt32(0 /*ordinal*/));
    }

    if (true == rs.ReadRelative(5))
    {
        MessageBox.Show("col1 = " + rs.GetInt32(0 /*ordinal*/));
    }

    if (true == rs.ReadLast())
    {
        MessageBox.Show("col1 = " + rs.GetInt32(0 /*ordinal*/));
    }

    if (true == rs.ReadPrevious())
    {
        MessageBox.Show("col1 = " + rs.GetInt32(0 /*ordinal*/));
    }

    if (true == rs.ReadAbsolute(5))
    {
        MessageBox.Show("col1 = " + rs.GetInt32(0 /*ordinal*/));
    }
}
catch (Exception e)
{
    MessageBox.Show(e.Message);
}
finally
{
    conn.Close();
}

Platforms

Windows CE, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows XP Professional x64 Edition, Windows XP SP2

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

Version Information

.NET Framework

Supported in: 3.0

.NET Compact Framework

Supported in: 2.0

See Also

Reference

SqlCeResultSet Class
SqlCeResultSet Members
System.Data.SqlServerCe Namespace