selectOne(queryWrapper); System.out.println(user); } /** * * 根据 Wrapper 条件,查询总记录数 * * * @param queryWrapper 实体对象 */ @Test public void selectCount() { QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper.eq("name", "lqf"); Integer count = mapper.select...
@TestpublicvoidqueryWrapperOne() { QueryWrapper<User> queryWrapper =new QueryWrapper<>(); queryWrapper. isNull("name") .ge("age",23) .isNotNull("email");// 逻辑删除int result = userMapper.delete(queryWrapper); System.out.println(result);// 最终的语句为:UPDATE user SET deleted=1 WHERE de...
publicvoidqueryWrapperThree() { QueryWrapper<User>queryWrapper=newQueryWrapper<>(); queryWrapper.between("age",20,30); Integercount=userMapper.selectCount(queryWrapper); System.out.println(count); } 1. 2. 3. 4. 5. 6. 7. 8. allEq allEq 全部 eq(或个别 isNull) 个别参数说明: params...
2.在mapper方法参数中用Param注解声明wrapper变量名称,必须是ew voidupdateBalanceByIds(@Param("ew")LambdaQueryWrapper<User>wrapper,@Param("amount")intamount); 3.在xml中自定义sql,并使用Wrapper条件 例子: Service接口 提供了一个iService接口,提供了大量用于增删改查的方法 增 删 改 查 查单个,查数目(cou...
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper; import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper; import com.baomidou.mybatisplus.extension.service.additional.query.impl.LambdaQueryChainWrapper; import com.mysql.cj.util.StringUtils; ...
QueryWrapper<User> wrapper = new QueryWrapper<>(); wrapper.between("age", 10, 20);//区间 Integer count = userMapper.selectCount(wrapper);//输出查询的数量selectCount System.out.println(count);} 测试四 @Testpublic void testWrapper4() { //模糊查询 QueryWrapper<User> wrapper = new QueryWrapp...
queryWrapper.like("s_name", "李"); List<Student> students = studentMapper.selectList(queryWrapper); System.out.println("students = " + students); } @Test public void query04(){ // 统计 selectCount // QueryWrapper<Student> queryWrapper = new QueryWrapper<>(); ...
public void selectCount() { QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper.eq("name", "lqf"); Integer count = mapper.selectCount(queryWrapper); System.out.println(count); } /** * * 根据 entity 条件,查询全部记录 * ...
你好,我尝试依照mybatis-plus的快速开始,来复现此问题,但没有成功,出现了问题下方的问题。麻烦大佬有时间看一下。 java.lang.IllegalStateException: Failed to load ApplicationContext 项目地址:https://github.com/RedCrazyGhost/QueryWarpperDemo RedCrazyGhostchanged the titleQueryWrapper条件查询SelectCount为0,Selec...
System.out.println("delete return count = " + result); } 二、eq、ne @Test public void testSelectOne() { QueryWrapper&lqdgpact;User> queryWrapper = new QueryWrapper<>(); queryWrapper.eq("name", "Tom"); Useruser = userMapper.selectOne(queryWrapper);//只能返回一条记录,多余一条则抛出异常 ...