我正在使用Oracle数据库，并有学生表：
学生桌：

| COLUMN      | TYPE          |
| ----------- | ------------- |
|  ID         | VARCHAR2(200) |
|  NAME       | VARCHAR2(200) |
|  AGE        | NUMBER(5)     |
|  MAIN_CITY  | VARCHAR2(200) |
|  GENDER     | VARCHAR2(50)  |
|  SCORE      | FLOAT(5)      |

'
我正在尝试将此SQL查询转换为query-dsl代码：

SELECT /*+ parallel(2)*/ *
FROM (WITH filtered_values(age, gender, main_city) AS
(
SELECT /*+ MATERIALIZE */ age, gender, main_city 
FROM Students
-- GET CONDITIONS FROM USER AND FILTER THE QUERY USING WHERE
)
SELECT * 
FROM (
SELECT age AS value, COUNT(*) AS row_count, 'age' AS column_name
FROM filtered_values
GROUP BY age
ORDER BY row_count)
WHERE rownum <= 5
UNION ALL (
SELECT * 
FROM (
SELECT gender AS value, COUNT(*) AS row_count, 'gender' AS column_name
FROM filtered_values
GROUP BY gender
ORDER BY row_count)
WHERE rownum <= 5)
UNION ALL (
SELECT * 
FROM (
SELECT main_city AS value, COUNT(*) AS row_count, 'main_city' AS column_name
FROM filtered_values
GROUP BY main_city
ORDER BY row_count)
WHERE rownum <= 5)
)

客户端提供的筛选器非常灵活，可以更改WITH查询，例如：
评分大于20时：
WITH filtered_values（年龄，性别，主要城市）AS（SELECT/*+ MATERIALIZE /年龄，性别，主要城市FROM分数〉20的学生）
其中城市为LA或NYC，评分在50 - 60之间：
WITH filtered_values（年龄，性别，主要城市）AS（SELECT/+ MATERIALIZE */年龄，性别，主要城市FROM学生WHERE主要城市IN（'LA '，' NYC'）AND分数〉= 50 AND分数〈= 60）
我使用的是QueryDsl版本5.0.0。
我创建了Java类：
学生：

@Data
@Entity
@NoArgsConstructor
@AllArgsConstructor
@Table(schema = "PROD", name = "Students")
public class Student implements Serializable {
@Id
@Column(name = "ID")
private String id;
@Column(name = "NAME")
private String name;
@Column(name = "AGE")
private int age;
@Column(name = "MAIN_CITY")
private String mainCity;
@Column(name = "SCORE")
private float score; 
}

聚合值：

@Data
@Entity
@NoArgsConstructor
@AllArgsConstructor
@Table(schema = "PROD", name = "NOT_REAL_TABLE")
public class AggregationValues {
private int age;
private String gender;
private String mainCity;
}

聚合结果行：

@Data
@NoArgsConstructor
@AllArgsConstructor
public class AggregationResultRow {
private String value;
private long rowCount;
private String columnName;
}

我的代码是：
注意，this.getConditions(aggregationsRequest)从客户端返回带有所有过滤器的BooleanBuilder。

private final QStudent table = QStudent.student;
private final QAggregationValues aggregationValues = QAggregationValues.aggregationValues;

public List<AggregationResultRow> getAggergations(AggregationRequest aggregationRequest) {
SubQueryExpression<AggregationValues> filteredValues = new BlazeJPAQuery<AggregationValues>(entityManager, criteriaBuilderFactory)
.select(Projections.constructor(AggregationValues.class, 
this.table.age,
this.table.gender,
this.table.mainCity))
.from(this.table)
.where(this.getConditions(aggregationRequest));

BlazeJPAQuery<AggregationResultRow> ageSelect = new BlazeJPAQuery<AggregationResultRow>(entityManager, criteriaBuilderFactory)
.with(this.aggregationValues, filteredValues)
.select(Projections.constructor(AggregationResultRow.class, this.aggregationValues.age.as("value"),
this.aggregationValues.count().as("row_count"),
Expressions.asString("age").as("column_name")))
.from(this.aggregationValues)
.groupBy(this.aggregationValues.age);

BlazeJPAQuery<AggregationResultRow> genderSelect = new BlazeJPAQuery<AggregationResultRow>(entityManager, criteriaBuilderFactory)
.with(this.aggregationValues, filteredValues)
.select(Projections.constructor(AggregationResultRow.class, this.aggregationValues.gender.as("value"),
this.aggregationValues.count().as("row_count"),
Expressions.asString("gender").as("column_name")))
.from(this.aggregationValues)
.groupBy(this.aggregationValues.gender);

BlazeJPAQuery<AggregationResultRow> mainCitySelect = new BlazeJPAQuery<AggregationResultRow>(entityManager, criteriaBuilderFactory)
.with(this.aggregationValues, filteredValues)
.select(Projections.constructor(AggregationResultRow.class, this.aggregationValues.mainCity.as("value"),
this.aggregationValues.count().as("row_count"),
Expressions.asString("main_city").as("column_name")))
.from(this.aggregationValues)
.groupBy(this.aggregationValues.mainCity);

return ageSelect.unionAll(genderSelect, mainCitySelect).fetch();
}

但我得到了异常-java.lang.IllegalArgumentException: Don't mix union and from
我已经尝试了更多的代码想法，但没有工作，这一个看起来最接近我的查询。
有什么想法吗？
非常感谢，我会非常感激的!