以书籍整理为例,书籍是一个单独的表,书籍类别是另一个表,通过书籍通过类别的ID可以查询到书籍类别的具体名称,下面分享一下代码:
//mapper
IPage<BookInfo> selectBookPage(IPage<BookInfo> page,
@Param
(Constants.WRAPPER) QueryWrapper<BookInfo> wrapper);
//service
public IPage<BookInfo> getOne(Params params){ IPage<BookInfo> pages = new Page<>(params.getPageNum(), params.getPageSize()); QueryWrapper<BookInfo> queryWrapper = new QueryWrapper<>(); if (!StringUtils.isBlank(params.getName())) { queryWrapper.like("book.name", "%" + params.getName() + "%"); //这里的列名不添加上去可能会有冲突,我两个表里都有name字段 } if (!StringUtils.isBlank(params.getAuthor())) { queryWrapper.like("author", "%" +params.getAge()+ "%"); } return bookMapper.selectBookPage(pages,queryWrapper); }
//bookMapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.example.mapper.BookMapper"> <resultMap id="orderMap" type="com.example.entity.vo.BookInfo"> <result property="id" column="id"/> <result property="name" column="name"/> <result property="price" column="price"/> <result property="author" column="author"/> <result property="press" column="press"/> <result property="img" column="img"/> <result property="typeId" column="typeId"/> <result property="typeName" column="typeName"/> </resultMap> <select id="selectBookPage" resultMap="orderMap"> select book.*,type.name as typeName from book left join type on book.typeId =type.id ${ew.customSqlSegment} </select> </mapper>
标签:queryWrapper,mybatisplus,QueryWrapper,book,params,IPage,多表,联查,书籍 From: https://www.cnblogs.com/Fooo/p/17847086.html