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@GetMapping("/list") public TableDataInfo list(Student student){ LambdaQueryWrapper<Student> lqw = new LambdaQueryWrapper<Student>(); lqw.eq(Student::getName, student.getName()); lqw.like(Student::getClass,student.getClass()); lqw.between("age",student.getAge1(),student.getAge2()); lqw.orderByAsc("age"); List<Student> list = studentService.list(lqw); } |
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select * from student where name = '?' and class like '%?%' and age between '?' and '?' order by '?' asc |
1.1、单表查询的基本用法
| 函数名 | 说明 | 例子 |
|---|---|---|
| eq | 等于 | 例：eq(“name”,“张子”) ===> name = ‘张子’ |
| ne | 不等于 | 例：ne(“name”,“张子”) ===> name <> ‘张子’ |
| gt | 大于 | 例：gt(“age”,“18”) ===> age>18 |
| lt | 小于 | 例：lt(“age”,“18”) ===> age<18 |
| between | 在值1到值2之间 | 例：between(“age”,18,30) ===> 18<age<30’ |
| like | 模糊查询 | 例：like(“name”,“张”) ===> name like ‘%张%’ |
| isNull | 字段为NULL | 例：isNull(“name”) ===> name is null |
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//Controller @GetMapping("/listAndClass") public TableDataInfo listAndClass(Student student) { QueryWrapper<Student > qw = new QueryWrapper<Student >(); if(StringUtils.isNotBlank(student.getName())){ qw.eq("s.name",student.getName()); } if(StringUtils.isNotBlank(student.getClassName())){ qw.like("c.name",student.getClassName()); } startPage(); List<Student > list = studentService.listAndClass(qw); return getDataTable(list); } //Service List<Student> listAndClass(QueryWrapper<Student> qw); //Service impl @Override public List<Student> listAndClass(QueryWrapper<Student> qw) { return this.getBaseMapper().listAndClass(qw); } //Mapper @Select("select s.*,c.name from student s left join class c on s.id = c.student_id "+ "${ew.customSqlSegment}") List<YwSpaqjgDj> listAndClass(@Param(Constants.WRAPPER) QueryWrapper<Student> qw); |
from:https://www.cnblogs.com/gongss/p/16727090.html