SqlCeResultSet.ReadPrevious Method
Positions the reader at the record pervious to the current record.
Namespace: System.Data.SqlServerCe
Assembly: System.Data.SqlServerCe (in System.Data.SqlServerCe.dll)
Syntax
'Declaration
Public Function ReadPrevious As Boolean
'Usage
Dim instance As SqlCeResultSet
Dim returnValue As Boolean
returnValue = instance.ReadPrevious()
public bool ReadPrevious()
public:
bool ReadPrevious()
member ReadPrevious : unit -> bool
public function ReadPrevious() : boolean
Return Value
Type: System.Boolean
True if the operation succeeded; otherwise, false.
Examples
The following example creates a ResultSet object and then calls several methods, including ReadPrevious.
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();
}