tsresultset.java

有关JDBC的使用一些编程实例,有关与数据库连接的代码

/*
 *
 * tsResultSet.java 
 *
 * Copyright 1996, Brian C. Jepson
 *                 ([e-mail])
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Result Set object for tinySQL.
 *
 */
import java.util.*;
import java.lang.*;
import java.io.*;

/*
 *
 * tsResultSet - object to hold query results
 *
 */
class tsResultSet {

  public Vector rows = new Vector();    // all of the rows
  public Vector columns = new Vector(); // all of the tsColumn objects
 
  /**
   * 
   * Returns the number of columns in the result set.
   *
   */
  public int numcols() {
    return columns.size();
  }

  /**
   *
   * Returns the number of rows in the result set.
   *
   */
  public int size() {
    return rows.size();
  }

  /**
   *
   * Returns the tsRow at a given row offset (starts with zero).
   *
   * @param i the row offset/index
   *
   */
  public tsRow rowAt(int i) {
    return (tsRow) rows.elementAt(i);
  }

  /**
   *
   * Returns the tsColumn at a given column offset (starts with zero).
   *
   * @param i the column offset/index
   *
   */
  public tsColumn columnAtIndex (int i) {
    return (tsColumn) columns.elementAt(i);
  }
 
  /** 
   *
   * Debugging method to dump out the result set
   *
   */
  public void PrintResultSet() {

    // print out column headers
    //
    StringBuffer header = new StringBuffer(" ");
    for (int k = 0; k < numcols(); k++) {

      tsColumn column = columnAtIndex(k);

      header.append(column.name);
      for (int f = 0; f < column.size - column.name.length(); f++) {
        header.append(' ');
      }
      header.append(' ');
    }
    System.out.println("");
    System.out.println(header);


    for (int i = 0; i < size(); i++) {

      StringBuffer printrow = new StringBuffer(" ");

      tsRow row = rowAt(i);

      for (int j = 0; j < numcols(); j++) {

        tsColumn column = columnAtIndex(j);
        String colval     = row.columnAsString(column);

        if (colval == null) {
          colval = "null";
        }
        int len = colval.length();

        printrow.append(colval);
        for (int f = 0; f < (column.size - len); f++) {
        printrow.append(' ');
        }
        printrow.append(' ');
      }
      System.err.println(printrow);
    }
  }

}