Mybatis Plus使用条件构造器增删改查功能的实现方法

/**
 * 图文课程管理Controller
 */
@RestController
@RequestMapping("/driver/imageCourse")
public class TImageCourseController extends BaseController {
    
    @Autowired
    private ITImageCourseService tImageCourseService;
    @Autowired
    private TImageCourseMapper tImageCourseMapper;
    
    // 具体接口...
}

/**
 * 图文课程管理Service接口
 */
public interface ITImageCourseService extends IService<TImageCourse> {
}

/**
 * 图文课程管理Service业务层处理
 */
@Service
public class TImageCourseServiceImpl extends ServiceImpl<TImageCourseMapper, TImageCourse> implements ITImageCourseService {
    @Autowired
    private TImageCourseMapper tImageCourseMapper;

}

// Service方法调用了Mapper方法 只是将insert()返回转换成了布尔值
@Override
public boolean save(T entity) {
    return retBool(baseMapper.insert(entity));
}

/**
 * 图文课程管理Mapper接口
 */
public interface TImageCourseMapper extends BaseMapper<TImageCourse> {
}

<?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.ruoyi.mapper.TRuralInfoMapper">

    <resultMap type="TRuralInfo" id="RuralInfoResult">
        <id     property="id"             column="id"           />
        <result property="cityName"       column="city_name"    />
        <result property="countyName"     column="county_name"  />
        <result property="townName"       column="town_name"    />
        <result property="villageName"    column="village_name" />
        <result property="checkCode"      column="check_code"   />
        <result property="parentLevel"    column="parent_level" />
        <result property="parentId"       column="parent_id"    />
        <result property="delFlag"        column="del_flag"     />
        <result property="createBy"       column="create_by"    />
        <result property="createTime"     column="create_time"  />
        <result property="updateBy"       column="update_by"    />
        <result property="updateTime"     column="update_time"  />
    </resultMap>

    <sql id="selectRuralInfoVo">
        select t_rural_info.id, city_name, county_name, town_name, village_name, check_code, parent_level, parent_id,
        t_rural_info.del_flag, t_rural_info.create_by, t_rural_info.create_time, t_rural_info.update_by, t_rural_info.update_time
        from t_rural_info
    </sql>

    <select id="getRuralInfoById" parameterType="Long" resultMap="RuralInfoResult">
        <include refid="selectRuralInfoVo"/>
        where id = #{id}
    </select>
</mapper>

/**
 * 新增图文课程管理
 */
@PostMapping
public AjaxResult add(@RequestBody TImageCourse tImageCourse)
{    
    ...
    return toAjax(tImageCourseMapper.insert(tImageCourse));
}

// 1、直接用new创建
// 创建对象的方式会更加灵活，可配合 if()...else 达到更灵活的sql拼接
LambdaQueryWrapper<TCenterPoint> wrapper = new LambdaQueryWrapper<>();
wrapper.eq(TCenterPoint::getPoint, 10.0);

// 2、静态方法创建 Wrappers.<>lambdaQuery()
// 构造器方法多为链式编程 可连写
Wrappers.<TCenterPoint>lambdaQuery().eq(TCenterPoint::getPoint, 10.0)

// 3、静态方法创建 Wrappers.query() 
// query可接受对象 字段不为null则自动拼接.eq()方法
Wrappers.query(tUserDetail)

/**
 * 源码
 * @param condition 执行条件 可省略
 * @param column    字段
 * @param val       值
 */
eq(boolean condition, R column, Object val)

or(Consumer<Param> consumer)
or(boolean condition, Consumer<Param> consumer)

// or (name = '李白' and status <> '活着')
or(i -> i.eq("name", "李白").ne("status", "活着"))

and(Consumer<Param> consumer)
and(boolean condition, Consumer<Param> consumer)

// and (name = '李白' and status <> '活着')
and(i -> i.eq("name", "李白").ne("status", "活着"))

/**
 * 修改图文课程管理
 */
@PutMapping
public AjaxResult edit(@RequestBody TImageCourse tImageCourse)
{
    return toAjax(tImageCourseMapper.updateById(tImageCourse));
}

/**
 * 删除图文课程管理
 */
@DeleteMapping("/{ids}")
public AjaxResult remove(@PathVariable Long[] ids) {
    return toAjax(tImageCourseMapper.deleteBatchIds(Arrays.asList(ids)));
}