SSM笔记-insert操作

1、对于支持自增主键的数据库,mybatis直接从数据库获取自增主键值,
作用：在进行添加操作后获取主键值

2、mapper配置文件中insert标签的属性：
①parameterType:可不写
②useGeneratedKeys:使用自增主键获取主键值策略
③keyProperty:指定对应主键属性名(即获取主键值之后,赋值给bean的哪个属性)

3、对于不支持自增主键的数据库,mybatis是从数据库的序列中获取主键值的,如：Oracle中的SEQ

4、mapper配置文件中insert标签的属性：
①keyProperty:指定查出主键封装到哪个Bean的哪个属性
②order:设置是在插入sql前还是后运行获取自增主键的sql(默认值：BEFORE/AFTER)
③resultType:查出数据的返回类型
插入语句的#{id}就是当order="BEFORE"时,selectKey获取到的id的值

5、BEFORE运行顺序：
①运行selectKey查询id的sql,查出id封装给Bean的对应属性
②运行插入sql,完成后可在java取出id属性的对应值
AFTER运行顺序：
①运行插入sql,从序列中取出新值作为id
②运行selectKey查询id的sql

当order=“BEFORE”时的写法：

	
		select xxx_SEQ.nextval from dual
	
	insert into info (id,name,password,description) values (#{id},#{name},#{password},#{description})


当order=“AFTER”时的写法：

	
		select xxx_SEQ.currval from dual
	
	insert into info (id,name,password,description) values (xxx_SEQ.nextval,#{name},#{password},#{description})

6、mybatis.xml

7、InfoMapper.xml

	
	
		insert into info (name,password,description) values (#{name},#{password},#{description})
	
	
	

8、dbConfig.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost/mybatis
jdbc.username=root
jdbc.password=

9、Info.java

package com.demo.ssmtest;


public class Info {

	Integer id;
	String name;
	String password;
	String description;
	
	public Info() {
		super();
	}
	
	public Info(Integer id, String name, String password, String description) {
		super();
		this.id = id;
		this.name = name;
		this.password = password;
		this.description = description;
	}

	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getDescription() {
		return description;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	@Override
	public String toString() {
		return "Info [id=" + id + ", name=" + name + ", password=" + password + ", description=" + description + "]";
	}
}

10、InfoMapper.java

package com.demo.ssmtest;

public interface InfoMapper {

	public Integer add(Info info);

}

11、TestMain.java

package com.demo.ssmtest;

import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class TestMain {
	
	
	public static void main(String[] args) throws Exception {
		test();
	}

	public static void test() throws Exception {

		String resource = "mybatis.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		
		SqlSession openSession = sqlSessionFactory.openSession();
		try {
			//增
			InfoMapper addMapper = openSession.getMapper(InfoMapper.class);
			Info add_Info = new Info(null,"nameNew","qweqwe","dddddddd");
			int add_Index = addMapper.add(add_Info);
			System.out.println("---"+add_Info.getId());
			System.out.println(add_Index);
		} finally {
			openSession.close();
		}

	}
}

12、项目目录

13、demo
https://download.csdn.net/download/qq_22778717/10714876