我们知道，在 MyBatis 中直接 DTO 映射查询的时候，写起来非常简单。只要字段对应上即可：
下面是对应的 Java 代码实例：
package com.alibaba.microtek.mapper.microtek;import com.alibaba.microtek.dto.SlowSqlTemplateDto;import com.alibaba.microtek.model.microtek.XxptSlowQueyInfo;import com.taobao.pandora.pandolet.annotation.Service;import org.apache.ibatis.annotations.ResultType;import org.apache.ibatis.annotations.Select;import java.util.List;public interface XxptSlowQueyInfoMapper {
@Select("SELECT app_name appName,sum(slow_template_count) c FROM `xxpt_slow_quey_info` GROUP BY app_name ORDER BY c desc limit 10") @ResultType(SlowSqlTemplateDto.class) List<SlowSqlTemplateDto> listSlowSqlTemplateDto();
}package com.alibaba.microtek.dto;public class SlowSqlTemplateDto {
String appName;
Integer c; public String getAppName() { return appName;
} public void setAppName(String appName) { this.appName = appName;
} public Integer getC() { return c;
} public void setC(Integer c) { this.c = c;
}
}在 JPA 中，稍微有点费事，但也还好。下面是一个完整的 Kotlin 代码实例
package com.slow.sql.speedoimport org.springframework.beans.factory.annotation.Autowiredimport org.springframework.web.bind.annotation.GetMappingimport org.springframework.web.bind.annotation.RestController@RestControllerclass XxptSlowQueyInfoController { @Autowired
lateinit var syncSlowSqlDataJob: SyncSlowSqlDataJob @Autowired
lateinit var xxptSlowQueyInfoDao: XxptSlowQueyInfoDao @GetMapping("/syncSlowSqlDataJob")
fun syncSlowSqlDataJob() {
syncSlowSqlDataJob.sync()
} @GetMapping("/listSlowSqlTemplateDto")
fun listSlowSqlTemplateDto(): List<SlowSqlTemplateDto> { return xxptSlowQueyInfoDao.listSlowSqlTemplateDto()
}
}package com.slow.sql.speedoimport org.springframework.data.jpa.repository.JpaRepositoryimport org.springframework.data.jpa.repository.Queryinterface XxptSlowQueyInfoDao : JpaRepository<XxptSlowQueyInfo, Long> { fun save(record: XxptSlowQueyInfo): XxptSlowQueyInfo @Query("""
SELECT
new com.slow.sql.speedo.SlowSqlTemplateDto( x.appName , sum(x.slowTemplateCount) )
FROM XxptSlowQueyInfo x
GROUP BY x.appName
ORDER BY sum(x.slowTemplateCount) desc
""")
fun listSlowSqlTemplateDto(): List<SlowSqlTemplateDto>
}package com.slow.sql.speedoimport com.alibaba.fastjson.annotation.JSONFieldimport java.util.*import javax.persistence.*@Entity@Table(name = "xxpt_slow_quey_info")class XxptSlowQueyInfo { @GeneratedValue(strategy = GenerationType.AUTO)
@Id
var id: Long? = null
@JSONField(name = "app_name")
var appName: String? = null
var owner: String? = null
var ops: String? = null
@JSONField(name = "need_optimize_slow_template_count")
var needOptimizeSlowTemplateCount: Int? = null
@JSONField(name = "need_optimize_slow_sql_count")
var needOptimizeSlowSqlCount: Int? = null
@JSONField(name = "slow_template_count")
var slowTemplateCount: Int? = null
@JSONField(name = "slow_sql_count")
var slowSqlCount: Int? = null
var date: Date? = null}
作者：一个会写诗的程序员
链接：https://www.jianshu.com/p/920e8f1a2dbb