psmethod.java

采用JAVA开发

package com.ywh.dbcp;

import java.sql.*;
/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: </p>
 * @author unascribed
 * @version 1.0
 */
public class PSMethod{

  private String _tableName;

  public PSMethod(String tableName){
    _tableName = tableName;
  }

  public String getSQLList(String [] fields){
    StringBuffer result = new StringBuffer();
    for (int i = 0; i < fields.length -1; i++) {
      result.append( fields[i] );
      result.append( " , " );
    }
    result.append( fields[fields.length-1] );
    return result.toString();
  }


  public boolean insert (Connection conn,
                         String [] fieldnames,
                         Object [] fieldvalues) throws SQLException {

    // Generate an array of question marks for the SQL template parameters
    String [] paras = new String[fieldnames.length];
    for (int i = 0; i < fieldnames.length; i++) {
      paras[i] = "?";
    }

    // Prepare the template
    String SQLstr = "INSERT INTO " + _tableName + " ( " +
                    getSQLList(fieldnames) + " ) VALUES ( " +
                    getSQLList(paras) + " ) ";
    PreparedStatement pstmt = conn.prepareStatement(SQLstr);
    // set parameter values
    for (int i = 0; i < fieldnames.length; i++) {
      pstmt.setObject(i + 1, fieldvalues[i]);
    }
    // execute SQL statement
    boolean succ = pstmt.execute();
    pstmt.close();
    return succ;
  }

  public Object [] select (Connection conn,
                           String [] fieldnames,
                           String idFieldname,
                           Object idValue) throws SQLException {

    Object [] result = new Object [fieldnames.length];

    // Prepared the template
    String SQLstr = "SELECT " + getSQLList(fieldnames) + " FROM " +
                    _tableName + " WHERE " + idFieldname + " = ?";

    PreparedStatement pstmt = conn.prepareStatement(SQLstr);
    // set parameter value
    pstmt.setObject(1, idValue);

    // execute SQL statement
    ResultSet rs = pstmt.executeQuery();
    // go to the first record
    rs.next();
    for ( int i = 0; i < fieldnames.length; i++) {
      result[i] = rs.getObject(i+1);
    }
    rs.close();
    pstmt.close();
    return result;
  }

}