Java 45---MyBatis框架（1）
导读
1.简介
2.MyBatis增删改查（包括模糊查询）
3.动态标签
简介
MyBatis是一个轻量级持久层ORM框架，可以完成表字段与实体类中属性之间的映射
MyBatis增删改查（包括模糊查询）
配置文件Configuration.xml
Book.java
package com.hala.entity;
public class Book {
private int bookId;
private String bookName;
private Double price;
private String author;
public Book() {
super();
}
public Book(String bookName, Double price, String author) {
super();
this.bookName = bookName;
this.price = price;
this.author = author;
}
public Book(int bookId, String bookName, Double price, String author) {
super();
this.bookId = bookId;
this.bookName = bookName;
this.price = price;
this.author = author;
}
public int getBookId() {
return bookId;
}
public void setBookId(int bookId) {
this.bookId = bookId;
}
public String getBookName() {
return bookName;
}
public void setBookName(String bookName) {
this.bookName = bookName;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
@Override
public String toString() {
return "Book [bookId=" + bookId + ", bookName=" + bookName + ", price=" + price + ", author=" + author + "]";
}
}
Book.xml
INSERT INTO my_book
(
book_name,
price,
author
)
VALUES
(
#{bookName},
#{price},
#{author}
)
UPDATE my_book SET
price=#{price}
WHERE
book_name = #{bookName}
DELETE FROM my_book WHERE book_id = #{bookId}
BookTest.java
package com.hala.test;
import java.io.IOException;
import java.io.Reader;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import com.hala.entity.Book;
public class BookTest {
private SqlSession ss=null;
@BeforeEach
public void before() throws IOException {
//Mybatis中操作数据使用sqlSession对象
//由sqlSessionFactory生成
//1.解析配置文件,并生成字符流
Reader reader=Resources.getResourceAsReader("Configuration.xml");
//2.根据文件配置信息生成SqlSessionFactory
SqlSessionFactory ssf=
new SqlSessionFactoryBuilder().build(reader);
//3.根据SqlSessionFactory获取SqlSession
ss=ssf.openSession();
//设置自动提交事务
//ss=ssf.openSession(true);
}
@AfterEach
public void after() {
ss.close();
}
//按照id查询单个（这里根据什么查询是在Book.xml处理模糊查询的方法：
1.传入参数时，自己处理
2.如上用concat函数
3.用下边bind标签处理
提高代码复用率的方法
动态标签
1.
2.替代WHERE关键字，去除多余的and
3.替代set关键字，并去除最后一个多余的逗号
4.
and name = #{name},
6.
7.
其他文件一致
Book.xml
UPDATE my_book
book_name LIKE #{bookName},
price= #{price},
author=#{author},
BookTest.java
package com.hala.test;
import java.io.IOException;
import java.io.Reader;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import com.hala.entity.Book;
public class BookTest {
private SqlSession ss=null;
@BeforeEach
public void before() throws IOException {
//Mybatis中操作数据使用sqlSession对象
//由sqlSessionFactory生成
//1.解析配置文件,并生成字符流
Reader reader=Resources.getResourceAsReader("Configuration.xml");
//2.根据文件配置信息生成SqlSessionFactory
SqlSessionFactory ssf=
new SqlSessionFactoryBuilder().build(reader);
//3.根据SqlSessionFactory获取SqlSession
ss=ssf.openSession();
//设置自动提交事务
//ss=ssf.openSession(true);
}
@AfterEach
public void after() {
ss.close();
}
@Test
public void query() {
Map map=new HashMap<>();
map.put("author", "J%");
List books=ss.selectList("Book.query",map);
for (Book book : books) {
System.out.println(book);
}
}
}
bind标签
trim标签
foreach标签
choose标签
