基于mybatis-plus|基于mybatis-plus QueryWrapper 排序的坑基于mybatis-plusQueryWrapper排序的

QueryWrapper排序的坑
条件构造器QueryWrapper

案例一
案例二
案例三
案例四

QueryWrapper排序的坑

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大致可以总结成上面的两句话。

条件构造器QueryWrapper 【基于mybatis-plus|基于mybatis-plus QueryWrapper 排序的坑】我们再搞几个实例来深入理解下条件构造器QueryWrapper的用法：

案例一
查询姓李的，并且出生日期范围是1993-02-09到1994-04-09的员工
sql实现：

SELECT * FROM t_employee WHERE DATE_FORMAT(birthday,'%Y-%m-%d')>='1993-02-09' AND DATE_FORMAT(birthday,'%Y-%m-%d')<='1994-04-09' AND NAME LIKE '李%'

mp实现：

/** * 查询姓李的，并且出生日期范围是1993-02-09到1994-04-09的员工 * sql：SELECT * FROM t_employee WHERE DATE_FORMAT(birthday,'%Y-%m-%d')>='1993-02-09' AND DATE_FORMAT(birthday,'%Y-%m-%d')<='1994-04-09' AND NAME LIKE '李%' */@Testpublic void selectByQueryWrapper3(){QueryWrapper queryWrapper=new QueryWrapper(); // QueryWrapper queryWrapper2=Wrappers.query(); queryWrapper.apply("DATE_FORMAT(birthday,'%Y-%m-%d')>={0} and DATE_FORMAT(birthday,'%Y-%m-%d')<={1}","1993-02-09","1994-04-09").likeRight("name","李"); List employeeList = employeeMapper.selectList(queryWrapper); System.out.println(employeeList); }

案例二
查询姓李的或者邮箱不为空并且是女性的员工
sql实现：

SELECT * FROM t_employee WHERE NAME LIKE '李%' OR (email IS NOT NULL AND gender ='女')

mp实现：

/** * 查询姓李的或者邮箱不为空并且是女性的员工 * sql：SELECT * FROM t_employee WHERE NAME LIKE '李%' OR (email IS NOT NULL AND gender ='女') */@Testpublic void selectByQueryWrapper4(){QueryWrapper queryWrapper=new QueryWrapper(); // QueryWrapper queryWrapper2=Wrappers.query(); queryWrapper.likeRight("name","李").or(wq->wq.isNotNull("email").eq("gender","女")); List employeeList = employeeMapper.selectList(queryWrapper); System.out.println(employeeList); }

案例三
查询姓李的并且邮箱不为空或者是女性的员工
sql实现：

SELECT * FROM t_employee WHERE NAME LIKE '李%' AND (email IS NOT NULL OR gender ='女')

mp实现：

/** * 查询姓李的并且邮箱不为空或者是女性的员工 * sql：SELECT * FROM t_employee WHERE NAME LIKE '李%' AND (email IS NOT NULL OR gender ='女') */@Testpublic void selectByQueryWrapper5(){QueryWrapper queryWrapper=new QueryWrapper(); // QueryWrapper queryWrapper2=Wrappers.query(); queryWrapper.likeRight("name","李").and(wq->wq.isNotNull("email").or().eq("gender","女")); List employeeList = employeeMapper.selectList(queryWrapper); System.out.println(employeeList); }

案例四
查询属于编号1,2,3部门的并且薪水小于等于3500的员工根据年龄从大到小排序显示
sql实现：

SELECT * FROM t_employee WHERE salary<=3500 AND departmentId IN (1,2,3) ORDER BY birthday ASC

mp实现：

/** * 查询属于编号1,2,3部门的并且薪水小于等于3500的员工根据年龄从大到小排序显示 * sql：SELECT * FROM t_employee WHERE salary<=3500 AND departmentId IN (1,2,3) ORDER BY birthday ASC */@Testpublic void selectByQueryWrapper6(){QueryWrapper queryWrapper=new QueryWrapper(); // QueryWrapper queryWrapper2=Wrappers.query(); queryWrapper.likeRight("name","李").and(wq->wq.isNotNull("email").or().eq("gender","女")); List employeeList = employeeMapper.selectList(queryWrapper); System.out.println(employeeList); }

以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。