Using a View Object to Insert and Delete Rows in Code

The following code example contains three methods in addition to main:

• addRow creates a row, fills in the columns, then adds it to the DEPT table.

  Key methods: ViewObject.createRow and Row.setAttribute. 

• deleteRow appends a WHERE clause to the default view of the DEPT table, executes the query, then deletes each row in the result set.

  Key method: ViewObject.removeCurrentRow

• commitAndShowChanges is a helper method that prints the updated table to the screen.

package d2e;
import oracle.jbo.*;
import oracle.jbo.domain.Number;
public class RowsDemo {
  public static void main(String[] args) {

    // Helper routine connects to the generic Application Module.
    ApplicationModule appMod =  
        QueryDemo.getGenericAppMod(JboContext.PLATFORM_LOCAL);

    // Specify the Java file that defines the VO.
    // Format: <package>
    String voDefFile = "d2e.DeptView";

    // Identify the View Object. Must be a valid Java identifier.
    String voName = "demoDeptVO";

    // Create the View Object within the context defined 
    // by the Application Module.
    ViewObject vo = appMod.createViewObject(voName, voDefFile);
    addRow(appMod, vo);
    deleteRow(appMod, vo);
  }

  public static void addRow(ApplicationModule appMod, ViewObject vo) {

    // Create a row and fill in the columns.
    Row newRow = vo.createRow();
    newRow.setAttribute("Deptno", new Number(14));
    newRow.setAttribute("Dname", "Pubs");
    newRow.setAttribute("Loc", "Honolulu");
    vo.insertRow(newRow);

    // Call a helper method.
    commitAndShowChanges(appMod);
  }

  public static void deleteRow(ApplicationModule appMod, ViewObject vo) {

    // Get row(s) to delete.
    vo.setWhereClause(" deptno > 10 and deptno < 20 ");

    // Delete row(s).
    vo.executeQuery();
    while (vo.hasNext()) {
      vo.next();
      vo.removeCurrentRow();
    }
    // Call a helper method.
    commitAndShowChanges(appMod);

  }
  public static void commitAndShowChanges(ApplicationModule appMod) {
    // Helper method to print updated table.

    try {
      appMod.getTransaction().commit();
    } 
    catch (Exception e) {
      System.out.println("\n Could not commit changes.");
      System.exit(0);

    }
    // Define and execute a simple SQL statement.
    String sqlStr = "select * from dept ";
    String dumpClass = "oracle.jbo.server.QueryDumpTab";
    String result = appMod.getTransaction().dumpQueryResult(sqlStr, dumpClass, null);

    // Print updated table.
    System.out.println(result);
  }
}

For more information on the dumpQueryResult() method, see Using Transaction Utility Methods.