SQL result set navigation

Schema information can be obtained with the Connection.prepareStatement and PreparedStatement.executeQuery methods. These methods query the UltraLite database with a user-defined SQL statement, and store the result set in a ResultSet object.

You can traverse ResultSet objects using the navigational methods in the ResultSet interface. This interface contains the following navigational methods:

afterLast¹ Position immediately after the last row.
beforeFirst¹ Position immediately before the first row.
first¹ Move to the first row.
last¹ Move to the last row.
next Move to the next row.
previous Move to the previous row.
relative(offset)¹ Move a specified number of rows relative to the current row, as specified by the signed offset value. Positive offset values move forward in the result set, relative to the current pointer position in the result set. Negative offset values move backward in the result set. An offset value of zero does not move the current location, but allows you to repopulate the row buffer.

¹ This method is not supported for UltraLite Java edition databases.

Retrieval example

The following example demonstrates how to query a user-defined SQL statement, retrieve a row from the result set using the next method, and access data from a specified column:

// Define a new SQL SELECT statement.
String sql_string = "SELECT column1, column2 FROM SampleTable";

// Create a new PreparedStatement from an existing connection.
PreparedStatement ps = conn.prepareStatement(sql_string);

// Create a new ResultSet to contain the query results of the SQL statement.
ResultSet rs = ps.executeQuery();

// Check if the PreparedStatement contains a ResultSet.
if (ps.hasResultSet()) {
     // Retrieve the column1 value from the first row using getString.
     String row1_col1 = rs.getString(1);
     // Get the next row in the table.
     if (rs.next()) {
          // Retrieve the value of column1 from the second row.
          String row2_col1 = rs.getString(1);
     }
}

rs.close();
ps.close();

Navigation example

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