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JbdcTemplate *** 作数据库

code•2022-4-25•java•阅读42

JbdcTemplate *** 作数据库,第1张

JbdcTemplate *** 作数据库（添加 *** 作）

1.对应数据库创建实体类

package com.atguigu.spring5.entity;

public class User {
    private String userId;
    private String username;
    private String ustatus;

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getUstatus() {
        return ustatus;
    }

    public void setUstatus(String ustatus) {
        this.ustatus = ustatus;
    }
}

xml配置文件

2.编写service和dao

（1）在dao进行数据库添加 *** 作

package com.atguigu.spring5.service;

import com.atguigu.spring5.dao.BookDao;
import com.atguigu.spring5.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class BookService {

    //注入dao
    @Autowired
    private BookDao bookDao;

    //添加的方法
    public void addBook(Book book){
        bookDao.add(book);
    }

}

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;

public interface BookDao {
    //添加的方法
    void add(Book book);

}

（2）调用JdbcTemplate对象里面update方法实现添加 *** 作

*有两个参数

*第一个参数：sql语句

 *第二个参数：可变参数，设置sql语句值

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class BookDaoImpl implements BookDao {
    //注入JdbcTemplate
    @Autowired
    private JdbcTemplate jdbcTemplate;

    //添加的方法

    @Override
    public void add(Book book) {
        //1.创建sql语句
        String sql = "insert into t_book values(?,?,?)";
        //2.调用方法实现
        Object[] args ={book.getUserid(), book.getUsername(), book.getUstatus()};
        //实现数据库的增加
        int update = jdbcTemplate.update(sql,args);
        System.out.println(update);
    }
}

（3）测试类

package com.atguigu.spring5.test;

import com.atguigu.spring5.entity.Book;
import com.atguigu.spring5.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.testng.annotations.Test;

public class TestBook {
    @Test
    public void testJdbcTemplate(){
        ApplicationContext context  = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);
        Book book = new Book();
        book.setUserId("1");
        book.setUsername("java");
        book.setUstatus("a");
        bookService.addBook(book);
    }
}

JdbcTemplate *** 作数据库（修改和删除）

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class BookDaoImpl implements BookDao {
    //注入JdbcTemplate
    @Autowired
    private JdbcTemplate jdbcTemplate;

    //添加的方法

    @Override
    public void add(Book book) {
        //1.创建sql语句
        String sql = "insert into t_book values(?,?,?)";
        //2.调用方法实现
        Object[] args ={book.getUserid(), book.getUsername(), book.getUstatus()};
        //实现数据库的增加
        int update = jdbcTemplate.update(sql,args);
        System.out.println(update);
    }
//修改
    @Override
    public void updateBook(Book book) {
        String sql = "update t_book set username=?,ustatus=? where user_id=?";
        Object[] args ={book.getUserid(), book.getUsername(), book.getUstatus()};
        int update = jdbcTemplate.update(sql,args);
        System.out.println(update);
    }
//删除
    @Override
    public void deleteBook(String id) {
        String sql = "delete from t_book where user_id=?";
        int update = jdbcTemplate.update(sql, id);
        System.out.println(update);
    }
}

测试类

package com.atguigu.spring5.test;

import com.atguigu.spring5.entity.Book;
import com.atguigu.spring5.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.testng.annotations.Test;
import sun.java2d.pipe.AlphaPaintPipe;

public class TestBook {
    @Test
    public void testDelete(){
        ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);
    //删除
        Book book = new Book();
        bookService.deleteBook("1");


    }
    @Test
    public void testUpdate(){
        ApplicationContext context  = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);
        //修改
        Book book = new Book();
        book.setUserid("1");
        book.setUsername("javaup");
        book.setUstatus("Abc");
        bookService.updateBook(book);
    }

    @Test
    public void testAdd(){
        ApplicationContext context  = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);

        //添加
     /*   Book book = new Book();
        book.setUserid("1");
        book.setUsername("java");
        book.setUstatus("A");
        bookService.addBook(book);*/




    }
}

JbdcTemplate *** 作数据库（查询返回某个值）

1.查询表里面有多少条记录，返回是某个值

2.使用jdbcTemplate实现查询返回某个值代码

jdbcTemplate.queryForObject(String sql,Class requiredType)
有两个参数

第一个参数：sql语句

第二个参数：返回类型Class

Book接口

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;
import org.springframework.stereotype.Repository;

import java.util.List;


public interface BookDao {
    //添加的方法
    void add(Book book);
//修改的方法
    void updateBook(Book book);
//删除的方法
    void deleteBook(String id);
//查询表中的记录数
    int selectConent();

//查询返回对象
    Book findBookInfo(String id);
    List findAllBook();
}

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class BookDaoImpl implements BookDao {
    //注入JdbcTemplate
    @Autowired
    private JdbcTemplate jdbcTemplate;



//查询
    @Override
    public int selectConent() {
        String sql = "select count(*) from t_book";
        Integer count = jdbcTemplate.queryForObject(sql, Integer.class);
        return count;
    }
    
}

测试类

package com.atguigu.spring5.test;

import com.atguigu.spring5.entity.Book;
import com.atguigu.spring5.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.testng.annotations.Test;
import sun.java2d.pipe.AlphaPaintPipe;

public class TestBook {
    @Test
    public void testSelect(){
        ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);
        //查询
        int count = bookService.findCount();
        System.out.println(count);

    }
}

JbdcTemplate *** 作数据库（查询返回对象）

1.场景：查询图书详情

2.JbdcTemplate实现查询返回对象

jdbcTemplate.queryForObject(String sql,RowMapper rowMapper,Object... args)

有三个参数：

第一个参数：sql语句

第二个参数：RowMapper，是接口，返回不同类型数据，使用这个接口里面实现类完成数据

第三个参数：sql语句值

Book类里面添加了toString（）方法

package com.atguigu.spring5.entity;

public class Book {
    private String userid;
    private String username;
    private String ustatus;

    public String getUserid() {
        return userid;
    }

    public void setUserid(String userid) {
        this.userid = userid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getUstatus() {
        return ustatus;
    }

    public void setUstatus(String ustatus) {
        this.ustatus = ustatus;
    }

    @Override
    public String toString() {
        return "Book{" +
                "userid='" + userid + '\'' +
                ", username='" + username + '\'' +
                ", ustatus='" + ustatus + '\'' +
                '}';
    }
}

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class BookDaoImpl implements BookDao {
    //注入JdbcTemplate
    @Autowired
    private JdbcTemplate jdbcTemplate;

//查询返回对象
    @Override
    public Book findBookInfo(String id) {
        String sql = "select * from t_book where user_id=?";
        //调用方法
        Book book = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper(Book.class), id);
        return book;
    }


}

测试类

package com.atguigu.spring5.test;

import com.atguigu.spring5.entity.Book;
import com.atguigu.spring5.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.testng.annotations.Test;
import sun.java2d.pipe.AlphaPaintPipe;

public class TestBook {
    @Test
    public void testSelect2(){
        ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);
        //查询返回对象
        Book book = bookService.findOne("2");
        System.out.println(book);
    }
}

JbdcTemplate *** 作数据库（查询返回集合）

1.场景：查询图书列表分页....

2.调用JdbcTemplate方法实现查询返回集合

package com.atguigu.spring5.dao;

import com.atguigu.spring5.entity.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public class BookDaoImpl implements BookDao {
    //注入JdbcTemplate
    @Autowired
    private JdbcTemplate jdbcTemplate;

   

//查询返回集合
    @Override
    public List findAllBook() {
        String sql ="select * from t_book";
        //调用方法
        List bookList = jdbcTemplate.query(sql, new BeanPropertyRowMapper(Book.class));
        return bookList;
    }


}

测试类

package com.atguigu.spring5.test;

import com.atguigu.spring5.entity.Book;
import com.atguigu.spring5.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.testng.annotations.Test;
import sun.java2d.pipe.AlphaPaintPipe;

import java.util.List;

public class TestBook {
    @Test
    public void testSelect3(){
        ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
        BookService bookService = context.getBean("bookService", BookService.class);
        //查询返回集合
        List all = bookService.findAll();
        System.out.println(all);
    }

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