mybatis之动态SQL操作之更新1）  更新条件不确定，需要根据情况产⽣SQL语法，这种情况叫动态SQL
/**
* 持久层*/
public class StudentDao {
/**
* 动态SQL--更新
*/
public void dynaSQLwithUpdate(Student student) throws Exception{
SqlSession sqlSession = SqlSession();
try{
sqlSession.update("mynamespace.dynaSQLwithUpdate",student);
}catch(Exception e){
e.printStackTrace();
throw e;
}finally{
sqlSessionmit();
MyBatisUtil.closeSqlSession();
sql中update什么意思}
}
public static void main(String[] args) throws Exception{
StudentDao dao = new StudentDao();
dao.dynaSQLwithUpdate(new Student(10,null,5000D));
dao.dynaSQLwithUpdate(new Student(10,"哈哈",null));
dao.dynaSQLwithUpdate(new Student(10,"哈哈",6000D));
}
}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-////DTD Mapper 3.0//EN"
"/dtd/mybatis-3-mapper.dtd">
<mapper namespace="mynamespace">
<update id="dynaSQLwithUpdate" parameterType="loaderman.Student">
update students
<set>
<if test="name!=null">
name=#{name},
</if>
<if test="sal!=null">
sal=#{sal},
</if>
</set>
where id=#{id}
</update>
</mapper>

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。