[Spring data jpa] 使用EntityManager 原生sql使用(详细)
spring data jpa - 动态原生SQL
前言
SpringData中们可是使用继承接口直接按照规则写方法名即可完成查询的方法，不需要写具体的实现，但是这样写又是不能满足我们的需求，比如子查询，SpringData中提供了@Query注解可以让我们写JPA的语句和原生的SQL语句，但是有些需求还是无法实现，这是可以用EntityManager来实现更加复杂的原生SQL，下面根据实际需求来介绍一下具体使用。
需求
根据考勤表中的status状态来计算每种状态的数量，status为两位 例如 25 为 迟到 + 工作日加班
![[Spring data jpa] 使用EntityManager 原生sql使用(详细)_第1张图片](http://img.e-com-net.com/image/info8/b7f55e6ff4f44199bc18bfe3840054f0.jpg)
代码片段
注入EntityManager对象
@PersistenceContext
private EntityManager entityManager;
原生SQL语句的拼接
1.查询语句
StringBuilder dataSql = new StringBuilder(
"select a.id as attendanceId," +
"p.person_no as personNo," +
"p.name as personName," +
"eg.name as groupName," +
"eg.id as groupId,"
//CASE when floor(status/10) = 1 then 1 else NULL end 判断status第一位数字，并计算其数量
+ "COUNT(CASE when floor(status/10) = 1 then 1 else NULL end) as absences,"
+ "COUNT(CASE when floor(status/10) = 2 then 1 else NULL end) as lateNumber,"
+ "COUNT(CASE when floor(status/10) = 3 then 1 else NULL end) as leaveEarly,"
+ "COUNT(CASE when floor(status/10) = 4 then 1 else NULL end) as normalDays,"
+ "COUNT(CASE when status_b = 1 then 1 else NULL end) as bAbsences,"
+ "COUNT(CASE when status_b = 2 then 1 else NULL end) as bLateNumber,"
+ "COUNT(CASE when status_b = 3 then 1 else NULL end) as bLeaveEarly,"
+ "COUNT(CASE when status_b = 4 then 1 else NULL end) as bNormalDays,"
+ "COUNT(CASE when status_c = 1 then 1 else NULL end) as cAbsences,"
+ "COUNT(CASE when status_c = 2 then 1 else NULL end) as cLateNumber,"
+ "COUNT(CASE when status_c = 3 then 1 else NULL end) as cLeaveEarly,"
+ "COUNT(CASE when status_c = 4 then 1 else NULL end) as cNormalDays,"
+ "COUNT(CASE when status_d = 1 then 1 else NULL end) as dAbsences,"
+ "COUNT(CASE when status_d = 2 then 1 else NULL end) as dLateNumber,"
+ "COUNT(CASE when status_d = 3 then 1 else NULL end) as dLeaveEarly,"
+ "COUNT(CASE when status_d = 4 then 1 else NULL end) as dNormalDays,"
//判断status第二位数字，并计算其数量
+ "COUNT(CASE when status%10 = 5 then 1 else NULL end) as workOvertime,"
+ "COUNT(CASE when status%10 = 6 then 1 else NULL end) as festivalOvertime,"
+ "COUNT(CASE when status%10 = 7 then 1 else NULL end) as holidayOvertime "
+ "from tdx_attendance_record a left join tdx_employee e on a.employee_id = e.id left join tdx_person p on e.person_id = p.id left join tdx_employee_group eg on e.group_id = eg.id");
2.where语句
StringBuilder whereSql = new StringBuilder(" WHERE e.attendance_rule_id is not null and a.deleted_flag = 0");
//根据传入条件动态拼接
if (null != siteId) {
whereSql.append(" and a.site_id = :siteId");
}
if (null != stateTime && null != endTime) {
whereSql.append(" and a.attendance_date BETWEEN :stateTime and :endTime");
}
if (StringUtils.isNotEmpty(personName)) {
whereSql.append(" and p.name like concat('%',:personName,'%')");
}
if (null != groupId && groupId != 0) {
whereSql.append(" and eg.id = :groupId");
}
分组语句和分页语句拼接
StringBuilder groupBySql = new StringBuilder(" GROUP BY a.employee_id");
dataSql.append(whereSql).append(groupBySql);
if (null != pageable) {
StringBuilder limitSql = new StringBuilder(" limit :offset,:pageSize");
dataSql.append(limitSql);
}
创建SQL并指定结果封装到指定对象中
Query dataQuery = entityManager.createNativeQuery(dataSql.toString());
dataQuery.unwrap(NativeQueryImpl.class).setResultTransformer(Transformers.aliasToBean(AttendanceStatisticsVo.class));
封装的VO对象
@Data
@NoArgsConstructor
@AllArgsConstructor
public class AttendanceStatisticsVo implements Serializable {
private static final long serialVersionUID = -8440165638031432031L;
private Integer attendanceId;
private String personNo;
private String personName;
private String groupName;
private Integer groupId;
//BigInteger 对应 sql count返回类型
private BigInteger absences;
private BigInteger lateNumber;
private BigInteger leaveEarly;
private BigInteger normalDays;
private BigInteger bAbsences;
private BigInteger bLateNumber;
private BigInteger bLeaveEarly;
private BigInteger bNormalDays;
private BigInteger cAbsences;
private BigInteger cLateNumber;
private BigInteger cLeaveEarly;
private BigInteger cNormalDays;
private BigInteger dAbsences;
private BigInteger dLateNumber;
private BigInteger dLeaveEarly;
private BigInteger dNormalDays;
private BigInteger workOvertime;
private BigInteger festivalOvertime;
private BigInteger holidayOvertime;
}
动态参数传入
//设置参数
if (null != siteId) {
//对应where等插叙条件语句中的参数 例： whereSql.append(" and a.site_id = :siteId") 中 ：siteId
dataQuery.setParameter("siteId", siteId);
}
if (null != stateTime && null != endTime) {
dataQuery.setParameter("stateTime", stateTime);
dataQuery.setParameter("endTime", endTime);
}
if (StringUtils.isNotEmpty(personName)) {
dataQuery.setParameter("personName", personName);
}
if (null != groupId && groupId != 0) {
dataQuery.setParameter("groupId", groupId);
}
if (null != pageable) {
Long offset = pageable.getOffset();
Integer pageSize = pageable.getPageSize();
dataQuery.setParameter("offset", offset);
dataQuery.setParameter("pageSize", pageSize);
}
执行返回结果
List<AttendanceStatisticsVo> resultList = dataQuery.getResultList();
具体代码
@PersistenceContext
private EntityManager entityManager;
@Override
@SuppressWarnings("unchecked")
public List<AttendanceStatisticsVo> pageAttendanceStatisticse(Integer siteId, Date stateTime, Date endTime, String statue, String personName, Pageable pageable, Integer groupId) {
StringBuilder dataSql = new StringBuilder(
"select a.id as attendanceId," +
"p.person_no as personNo," +
"p.name as personName," +
"eg.name as groupName," +
"eg.id as groupId,"
+ "COUNT(CASE when floor(status/10) = 1 then 1 else NULL end) as absences,"
+ "COUNT(CASE when floor(status/10) = 2 then 1 else NULL end) as lateNumber,"
+ "COUNT(CASE when floor(status/10) = 3 then 1 else NULL end) as leaveEarly,"
+ "COUNT(CASE when floor(status/10) = 4 then 1 else NULL end) as normalDays,"
+ "COUNT(CASE when status_b = 1 then 1 else NULL end) as bAbsences,"
+ "COUNT(CASE when status_b = 2 then 1 else NULL end) as bLateNumber,"
+ "COUNT(CASE when status_b = 3 then 1 else NULL end) as bLeaveEarly,"
+ "COUNT(CASE when status_b = 4 then 1 else NULL end) as bNormalDays,"
+ "COUNT(CASE when status_c = 1 then 1 else NULL end) as cAbsences,"
+ "COUNT(CASE when status_c = 2 then 1 else NULL end) as cLateNumber,"
+ "COUNT(CASE when status_c = 3 then 1 else NULL end) as cLeaveEarly,"
+ "COUNT(CASE when status_c = 4 then 1 else NULL end) as cNormalDays,"
+ "COUNT(CASE when status_d = 1 then 1 else NULL end) as dAbsences,"
+ "COUNT(CASE when status_d = 2 then 1 else NULL end) as dLateNumber,"
+ "COUNT(CASE when status_d = 3 then 1 else NULL end) as dLeaveEarly,"
+ "COUNT(CASE when status_d = 4 then 1 else NULL end) as dNormalDays,"
+ "COUNT(CASE when status%10 = 5 then 1 else NULL end) as workOvertime,"
+ "COUNT(CASE when status%10 = 6 then 1 else NULL end) as festivalOvertime,"
+ "COUNT(CASE when status%10 = 7 then 1 else NULL end) as holidayOvertime "
+ "from tdx_attendance_record a left join tdx_employee e on a.employee_id = e.id left join tdx_person p on e.person_id = p.id left join tdx_employee_group eg on e.group_id = eg.id");
//拼接where条件
StringBuilder whereSql = new StringBuilder(" WHERE e.attendance_rule_id is not null and a.deleted_flag = 0");
if (null != siteId) {
whereSql.append(" and a.site_id = :siteId");
}
if (null != stateTime && null != endTime) {
whereSql.append(" and a.attendance_date BETWEEN :stateTime and :endTime");
}
if (StringUtils.isNotEmpty(personName)) {
whereSql.append(" and p.name like concat('%',:personName,'%')");
}
if (null != groupId && groupId != 0) {
whereSql.append(" and eg.id = :groupId");
}
StringBuilder groupBySql = new StringBuilder(" GROUP BY a.employee_id");
dataSql.append(whereSql).append(groupBySql);
if (null != pageable) {
StringBuilder limitSql = new StringBuilder(" limit :offset,:pageSize");
dataSql.append(limitSql);
}
Query dataQuery = entityManager.createNativeQuery(dataSql.toString());
dataQuery.unwrap(NativeQueryImpl.class).setResultTransformer(Transformers.aliasToBean(AttendanceStatisticsVo.class));
//设置参数
if (null != siteId) {
dataQuery.setParameter("siteId", siteId);
}
if (null != stateTime && null != endTime) {
dataQuery.setParameter("stateTime", stateTime);
dataQuery.setParameter("endTime", endTime);
}
if (StringUtils.isNotEmpty(personName)) {
dataQuery.setParameter("personName", personName);
}
if (null != groupId && groupId != 0) {
dataQuery.setParameter("groupId", groupId);
}
if (null != pageable) {
Long offset = pageable.getOffset();
Integer pageSize = pageable.getPageSize();
dataQuery.setParameter("offset", offset);
dataQuery.setParameter("pageSize", pageSize);
}
List<AttendanceStatisticsVo> resultList = dataQuery.getResultList();
return dataQuery.getResultList();
}