dbcp和jdbc程序教程实例3——数据库的查询

package Karl.Doenitz;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class ShopInformationDisplay {//得到商品属性类public String getname(String name) {//得到商品名称try {Connection con = null;con = Temple.getConnection();String sql = "select * from shoplist where name = "+"'"+name+"'";PreparedStatement ps = con.prepareStatement(sql);ResultSet rs = null;rs = ps.executeQuery();if(rs.next()){System.out.println(rs.getString("name"));return rs.getString("name");}    else{               System.out.println("失败，商品"+name+"不存在！");               return "noresult";          } } catch (SQLException e) {e.printStackTrace();}return "ok";}public String getkind(String name) {//得到商品类型try {Connection con = null;con = Temple.getConnection();String sql = "select * from shoplist where name = "+"'"+name+"'";PreparedStatement ps = con.prepareStatement(sql);ResultSet rs = null;rs = ps.executeQuery();if(rs.next()){System.out.println(rs.getString("kind"));return rs.getString("kind");}    else{               System.out.println("失败，商品"+name+"不存在！");               return "noresult";          } } catch (SQLException e) {e.printStackTrace();}return "ok";}public String getsize(String name) {//得到商品尺寸大小try {Connection con = null;con = Temple.getConnection();String sql = "select * from shoplist where name = "+"'"+name+"'";PreparedStatement ps = con.prepareStatement(sql);ResultSet rs = null;rs = ps.executeQuery();if(rs.next()){System.out.println(rs.getString("size"));return rs.getString("size");}    else{               System.out.println("失败，商品"+name+"不存在！");               return "noresult";          } } catch (SQLException e) {e.printStackTrace();}return "ok";}public String getprice(String name) {//获取商品价格try {Connection con = null;con = Temple.getConnection();String sql = "select * from shoplist where name = "+"'"+name+"'";PreparedStatement ps = con.prepareStatement(sql);ResultSet rs = null;rs = ps.executeQuery();if(rs.next()){System.out.println(rs.getString("price"));return rs.getString("price");}    else{               System.out.println("失败，商品"+name+"不存在！");               return "noresult";          } } catch (SQLException e) {e.printStackTrace();}return "ok";}public String getphone(String name) {//获取商家电话联系方式try {Connection con = null;con = Temple.getConnection();String sql = "select * from shoplist where name = "+"'"+name+"'";PreparedStatement ps = con.prepareStatement(sql);ResultSet rs = null;rs = ps.executeQuery();if(rs.next()){System.out.println(rs.getString("phone"));return rs.getString("phone");}    else{               System.out.println("失败，商品"+name+"不存在！");               return "noresult";          } } catch (SQLException e) {e.printStackTrace();}return "ok";}public static void main(String args[]){ShopInformationDisplay sid = new ShopInformationDisplay();String s = sid.getsize("美羊羊");sid.getkind("喜羊羊");sid.getname("美羊羊");sid.getphone("喜羊羊");sid.getprice("美羊羊");System.out.println(s); }}

好了，今天的例子就讲到这里了，同学们有什么不理解的可以自己多敲几遍例子就明白了。