使用fill自动填充
@TableField(fill = FieldFill.INSERT) @TableField(fill = FieldFill.DEFAULT)
自动填充类型
package com.example.mybatisplus.handler;
import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;
import java.util.Date;
@Component
public class MyMateObjectHandler implements MetaObjectHandler {
@Override
public void insertFill(MetaObject metaObject) {
this.setFieldValByName("create_time", new Date(), metaObject);
this.setFieldValByName("update_time", new Date(), metaObject);
}
@Override
public void updateFill(MetaObject metaObject) {
this.setFieldValByName("update_time", new Date(), metaObject);
}
}
悲观锁
直接锁死
乐观锁
不锁死
@Version private Integer version;
解决并发问题
package com.example.mybatisplus.config;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.OptimisticLockerInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
//乐观锁
@Configuration
public class MybatisConfig {
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {
// 实例化乐观锁
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
// 添加乐观锁插件
interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());
return interceptor;
}
}
@Test
void test15() {
QueryWrapper<Users> wrapper = new QueryWrapper<>();
// wrapper.like("username","1");
Page<Users> page = new Page<>(1,2); //当前页面,一个页面多少条
usersMapper.selectPage(page,wrapper);
List<Users> records = page.getRecords();//查询出来的结果集
long pages = page.getPages();
long total = page.getTotal();
long current = page.getCurrent();
for (Users user : records) {
System.out.println(user+",pages:"+pages+",total:"+total+",current:"+current);
}
System.out.println(records);
}
分页查询,以及返回的数据
当前页面等的数据.
mybatis代码生成器
autogenerator 自动代码生成器