Java使用PreparedStatement接口及ResultSet结果集的方法示例

本文实例讲述了Java使用PreparedStatement接口及ResultSet结果集的方法。分享给大家供大家参考，具体如下：

说明：

1.PreparedStatement接口继承Statement,它的实例包含已编译的SQL语句，执行速度要快于Statement。

2.PreparedStatement继承了Statement的所有功能，三种方法executeUpdate、executeQuery、execute不再需要参数。

3.在JDBC应用中，一般都用PreparedStatement，而不是Statement。

便于操作，先做一些封装：

对连接数据库，关闭连接封装，在之前博客中已经提到DbUtil.java;

对数据库表进行封装，这里是对我的数据库中comp表进行操作，因此封装如下：

package com.mysqltest.jdbc.modelComp;
public class CompMember {
  private int id;
  private String name;
  private int age;
  private double salary;
  /**
   * 构造函数1
   * @param name
   * @param age
   * @param salary
   */
  public CompMember(String name, int age, double salary) {
    super();
    this.name = name;
    this.age = age;
    this.salary = salary;
  }
  /**
   * 重载构造函数
   * @param id
   * @param name
   * @param age
   * @param salary
   */
  public CompMember(int id, String name, int age, double salary) {
    super();
    this.id = id;
    this.name = name;
    this.age = age;
    this.salary = salary;
  }
  /**
   * get,set方法
   */
  public int getId() {
    return id;
  }
  public void setId(int id) {
    this.id = id;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public int getAge() {
    return age;
  }
  public void setAge(int age) {
    this.age = age;
  }
  public double getSalary() {
    return salary;
  }
  public void setSalary(double salary) {
    this.salary = salary;
  }
  @Override
  /**
   * 改写toString,使得显示更好
   */
  public String toString() {
    return "["+this.id+"]"+this.name+","+this.age+","+this.salary;
  }
}

然后利用PreparedStatement接口实现增的操作：

package com.mysqltest.jdbc.xiao1;
import java.sql.Connection;
import java.sql.PreparedStatement;
import com.mysqltest.jdbc.modelComp.CompMember;
import com.mysqltest.jdbc.util.DbUtil;
public class PstatementTest {
  private static DbUtil dbUtil = new DbUtil();
  /**
   * 用PreparedStatement添加成员
   * @param mem
   * @return
   * @throws Exception
   */
  private static int addMember(CompMember mem) throws Exception{
    Connection con = dbUtil.getCon();
    String sql = "insert into comp values(null,?,?,?)";
    PreparedStatement pstmt = con.prepareStatement(sql);
    pstmt.setString(1, mem.getName());
    pstmt.setInt(2, mem.getAge());
    pstmt.setDouble(3, mem.getSalary());
    int result = pstmt.executeUpdate();//中间不用传入sql
    dbUtil.close(pstmt, con); //preparedStatement是子类，用父类关闭也行
    return result;
  }
  public static void main(String[] args) throws Exception {
    CompMember mem = new CompMember("刘翔", 24, 8000.00);
    int result = addMember(mem);
    if (result==1) {
      System.out.println("添加成功");
    } else {
      System.out.println("添加失败");
    }
  }
}

再利用PreparedStatement接口实现查询，并运用ResultSet结果集：

package com.mysqltest.jdbc.xiao2;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import com.mysqltest.jdbc.modelComp.CompMember;
import com.mysqltest.jdbc.util.DbUtil;
public class ResultsetTest {
  private static DbUtil dbUtil = new DbUtil();
  /**
   * 遍历查询结果
   * @throws Exception
   */
  @SuppressWarnings("unused")
  private static void listMem1() throws Exception {
    Connection con = dbUtil.getCon();// 获取连接
    String sql = "select * from comp";
    PreparedStatement pstmt = con.prepareStatement(sql);
    ResultSet rs = pstmt.executeQuery();// 返回结果集
    // next()将光标向后一行
    while (rs.next()) {
      int id = rs.getInt(1);// 获取第一列的值id
      String name = rs.getString(2);//
      int age = rs.getInt(3);
      double salary = rs.getDouble(4);
      System.out.println("编号：" + id + "姓名：" + name + "年龄：" + age + "工资：" + salary);
      System.out.println("+====================================+");
    }
  }
  /**
   * 遍历查询结果方法2
   * @throws Exception
   */
  @SuppressWarnings("unused")
  private static void listMem2() throws Exception {
    Connection con = dbUtil.getCon();// 获取连接
    String sql = "select * from comp";
    PreparedStatement pstmt = con.prepareStatement(sql);
    ResultSet rs = pstmt.executeQuery();// 返回结果集
    // next()将光标向后一行
    while (rs.next()) {
      int id = rs.getInt("id");// 获取第一列的值id
      String name = rs.getString("name");//
      int age = rs.getInt("age");
      double salary = rs.getDouble("salary");
      System.out.println("编号：" + id + "姓名：" + name + "年龄：" + age + "工资：" + salary);
      System.out.println("+====================================+");
    }
  }
  private static List<CompMember> listMem3() throws Exception{
    List<CompMember> memList = new ArrayList<CompMember>();
    Connection con = dbUtil.getCon();// 获取连接
    String sql = "select * from comp";
    PreparedStatement pstmt = con.prepareStatement(sql);
    ResultSet rs = pstmt.executeQuery();// 返回结果集
    // next()将光标向后一行
    while (rs.next()) {
      int id = rs.getInt("id");// 获取第一列的值id
      String name = rs.getString("name");//
      int age = rs.getInt("age");
      double salary = rs.getDouble("salary");
      CompMember mem = new CompMember(id, name, age, salary);
      memList.add(mem);//添加到List中
    }
    return memList;
  }
  public static void main(String[] args) throws Exception {
//    listMem1();
//    listMem2();
    List<CompMember> memList = listMem3();
    for (CompMember mem : memList) { //遍历集合的每个元素
      System.out.println(mem);
    }
  }
}

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