4.使用 PreparedStatement 接口实现增，删，改操作

package com.java1234.jdbc.model;

/**
* 图书模型
* @author caofeng
*
*/
public class Book {

private int id;
private String bookName;
private float price;
private String author;
private int bookTypeId;

public Book(int id, String bookName, float price, String author,
int bookTypeId) {
super();
this.id = id;
this.bookName = bookName;
this.price = price;
this.author = author;
this.bookTypeId = bookTypeId;
}
public Book(String bookName, float price, String author, int bookTypeId) {
super();
this.bookName = bookName;
this.price = price;
this.author = author;
this.bookTypeId = bookTypeId;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getBookName() {
return bookName;
}
public void setBookName(String bookName) {
this.bookName = bookName;
}
public float getPrice() {
return price;
}
public void setPrice(float price) {
this.price = price;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public int getBookTypeId() {
return bookTypeId;
}
public void setBookTypeId(int bookTypeId) {
this.bookTypeId = bookTypeId;
}

}

package com.java1234.jdbc.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

import com.mysql.jdbc.PreparedStatement;

public class DbUtil {

// 数据库地址
private static String dbUrl="jdbc:mysql://localhost:3306/db_book";
// 用户名
private static String dbUserName="root";
// 密码
private static String dbPassword="123456";
// 驱动名称
private static String jdbcName="com.mysql.jdbc.Driver";

/**
* 获取数据库连接
* @return
* @throws Exception
*/
public Connection getCon()throws Exception{
Class.forName(jdbcName);
Connection con=DriverManager.getConnection(dbUrl, dbUserName, dbPassword);
return con;
}

/**
* 关闭连接
* @param con
* @throws Exception
*/
public void close(Statement stmt,Connection con)throws Exception{
if(stmt!=null){
stmt.close();
if(con!=null){
con.close();
}
}
}

/**
* 关闭连接
* @param con
* @throws Exception
*/
public void close(PreparedStatement pstmt,Connection con)throws Exception{
if(pstmt!=null){
pstmt.close();
if(con!=null){
con.close();
}
}
}
}

package com.java1234.jdbc.chap04.sec02;

import java.sql.Connection;
import java.sql.PreparedStatement;

import com.java1234.jdbc.model.Book;
import com.java1234.jdbc.util.DbUtil;

public class Demo1 {

private static DbUtil dbUtil=new DbUtil();

/**
* 添加图书
* @param book
* @return
* @throws Exception
*/
private static int addBook(Book book)throws Exception{
Connection con=dbUtil.getCon(); // 获取连接
String sql="insert into t_book values(null,?,?,?,?)";
PreparedStatement pstmt=con.prepareStatement(sql);
pstmt.setString(1, book.getBookName());  // 给第一个坑设置值
pstmt.setFloat(2, book.getPrice());  // 给第二个坑设置值
pstmt.setString(3, book.getAuthor()); // 给第三个坑设置值
pstmt.setInt(4, book.getBookTypeId());  // 给第四个坑设置值
int result=pstmt.executeUpdate();
dbUtil.close(pstmt, con);
return result;
}

public static void main(String[] args) throws Exception{
Book book=new Book("Java叉叉2", 1, "叉叉", 1);
int result=addBook(book);
if(result==1){
System.out.println("添加成功！");
}else{
System.out.println("添加失败！");
}
}
}

package com.java1234.jdbc.chap04.sec03;

import java.sql.Connection;
import java.sql.PreparedStatement;

import com.java1234.jdbc.model.Book;
import com.java1234.jdbc.util.DbUtil;

public class Demo1 {

private static DbUtil dbUtil=new DbUtil();

/**
* 更新图书
* @param book
* @return
* @throws Exception
*/
private static int updateBook(Book book)throws Exception{
Connection con=dbUtil.getCon();
String sql="update t_book set bookName=?,price=?,author=?,bookTypeId=? where id=?";
PreparedStatement pstmt=con.prepareStatement(sql);
pstmt.setString(1, book.getBookName());
pstmt.setFloat(2, book.getPrice());
pstmt.setString(3, book.getAuthor());
pstmt.setInt(4, book.getBookTypeId());
pstmt.setInt(5, book.getId());
int result=pstmt.executeUpdate();
dbUtil.close(pstmt, con);
return result;
}

public static void main(String[] args) throws Exception{
Book book=new Book(12,"K2", 2, "K", 2);
int result=updateBook(book);
if(result==1){
System.out.println("更新成功！");
}else{
System.out.println("更新失败！");
}
}
}

package com.java1234.jdbc.chap04.sec04;

import java.sql.Connection;
import java.sql.PreparedStatement;

import com.java1234.jdbc.util.DbUtil;

public class Demo1 {

private static DbUtil dbUtil=new DbUtil();

/**
* 删除图书
* @param id
* @return
* @throws Exception
*/
private static int deleteBook(int id)throws Exception{
Connection con=dbUtil.getCon();
String sql="delete from t_book where id=?";
PreparedStatement pstmt=con.prepareStatement(sql);
pstmt.setInt(1, id);
int result=pstmt.executeUpdate();
dbUtil.close(pstmt, con);
return result;
}

public static void main(String[] args)throws Exception {
int result=deleteBook(12);
if(result==1){
System.out.println("删除成功！");
}else{
System.out.println("删除失败！");
}
}
}