JDBC(三)——使用Statement接口对数据库实现增删改操作(2)

上一篇博客里说到用Statement接口对数据库实现增删改操作,其中的sql语句是我们直接手写的;

但在实际开发过程中,数据都是从前台直接获取的,而不是自己手动导入的;

1.在添加图书这个操作中,我们可以写一个添加方法:

//增加图书的方法
	private static int addBook(int id,String bookName,double price,String author,int bookTypeId) throws Exception{
		//引用工具类dbUtil
		DbUtil dbUtil=new DbUtil();
		//连接数据库
		Connection con=dbUtil.getCon();
		//获取Statement接口
		Statement stmt=con.createStatement();
		//sql语句
		String sql="insert into t_book values("+id+",'"+bookName+"',"+price+",'"+author+"',"+bookTypeId+")";
		//执行sql语句
		int result=stmt.executeUpdate(sql);
		//关闭数据库,将关闭的方法封装到工具类里面的close()方法里面
		dbUtil.close(stmt, con);
		return result;
	}

这样的sql语句就可以用导入的数据,在进行测试之后:

public static void main(String[] args) throws Exception {
		int result=addBook(5,"Web前端",63.0,"大牛",3);
		if(result==1){
			System.out.println("数据添加成功!");
		}else{
			System.out.println("数据添加失败!");
		}
	}

结果:

2.但是这样其实也并不好,我们可以用面向对象思想来写一个Model类,将书籍的各个属性进行封装成一个Book类;

package Month01.Day08.Model;

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 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;
	}
	
}

然后再写addBook2()方法:

package Month01.Day08.Demo01;

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

import Month01.Day08.DbUtil.DbUtil;
import Month01.Day08.Model.Book;

public class insert_sql_2 {

	//增加图书的方法
	private static int addBook2(Book book) throws Exception{
		DbUtil dbUtil=new DbUtil();
		Connection con=dbUtil.getCon();
		Statement stmt=con.createStatement();
		String sql="insert into t_book values("+book.getId()+",'"+book.getBookName()+"',"+
					book.getPrice()+",'"+book.getAuthor()+"',"+book.getBookTypeId()+")";
		int result=stmt.executeUpdate(sql);
		return result;
	}
	

	public static void main(String[] args) throws Exception {
		Book book=new Book(6,"Java设计思想",45,"亨得利",4);
		int result=addBook2(book);
		if(result==1){
			System.out.println("数据添加成功!");
		}else{
			System.out.println("数据添加失败!");
		}
	}
}

测试之后:

可以看到面向对象的思想还是很方便的! 

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转载自blog.csdn.net/qq_37084904/article/details/86100816