DB2®ResultSet.ReadFirst Method

Syntax

[Visual Basic]
Public Function ReadFirst As Boolean
[C#]
public bool ReadFirst ()
[C++]
public:
bool ReadFirst ()
[JScript]
public function ReadFirst () : Boolean

Return value

true if the newly assumed position has a record (regardless if it was deleted); otherwise, false.

Remarks

For non-scrollable cursors, the ReadFirst method will return true and move to the first record if the cursor has not yet read a record from the result set. If the cursor is on the first row of the result set, ReadFirst will return true and remain on the first row. If the cursor is on any other row in the result set, ReadFirst will throw an exception.

The default position of the DB2ResultSet is before the first record. Therefore, you must call Read, ReadFirst, ReadLast, or ReadAbsolute before any data.

Example

[C#] The following example demonstrates how to determine if the DB2ResultSet instance is scrollable, and then how to read the first row in the result set.

[C#]
  public static string getSalesData(DB2Connection conn)
  {
    string salesQuery = "SELECT * FROM SALES";
    string salesData = "";
    DB2Command cmd = new DB2Command(salesQuery, conn);
    DB2ResultSet salesRS = cmd.ExecuteResultSet(
      DB2ResultSetOptions.Scrollable |
      DB2ResultSetOptions.Sensitive |
      DB2ResultSetOptions.SkipDeleted);

    if (salesRS.Scrollable)
    {
      if (salesRS.ReadFirst())
      {
        salesData = salesRS.GetDB2Date(0).ToString();
        salesData += ", " + salesRS.GetDB2String(1).ToString();
        salesData += ", " + salesRS.GetDB2String(2).ToString();
        salesData += ", " + salesRS.GetDB2Int32(3).ToString();
      }
    }

    return salesData;
  }