QueryDSL：舍入期间语法错误解析

Question

@Embeddable
public class Birthday {

    private LocalDate value;

    // Constructors, getters and setters
}

实体：

@Entity
public class Person {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private Birthday birthday;

     // Constructors, getters and setters
}

除以3查询：

List<Person> sortedPersons = query.selectFrom(person)
                               .orderBy(person.birthday.value.month().divide(3).ceil().asc())
                                .fetch();

使用模板查询：

 List<Person> sortedPersons = query.selectFrom(person)
                                   .orderBy(Expressions.dateTemplate(Integer.class, "QUARTER({0})", person.birthday.value).asc())
                                    .fetch();

错误：

Caused by: org.eclipse.persistence.exceptions.JPQLException:
Exception Description: Syntax error parsing [select 
from Person person
order by ceil(extract(month from person.birthday.value) / 3) asc].
[3165, 3254] The order by item is not a valid expression.
    at org.eclipse.persistence.internal.jpa.jpql.HermesParser.buildException(HermesParser.java:157) ~[com.ibm.websphere.appserver.thirdparty.eclipselink.2.7_1.0.76.jar:?]
    at [internal classes]
    at com.querydsl.jpa.impl.AbstractJPAQuery.createQuery(AbstractJPAQuery.java:101) ~[querydsl-jpa-4.2.2.HL-20230109.202119-8.jar:?]
    at com.querydsl.jpa.impl.AbstractJPAQuery.createQuery(AbstractJPAQuery.java:94) ~[querydsl-jpa-4.2.2.HL-20230109.202119-8.jar:?]
    at com.querydsl.jpa.impl.AbstractJPAQuery.fetch(AbstractJPAQuery.java:201) ~[querydsl-jpa-4.2.2.HL-20230109.202119-8.jar:?]

生日字段以 DATE 形式存储在数据库中

问题是，如果我删除方法

.ceil()

，那么一切都会很好，但四舍五入对我来说很重要，而无需四舍五入我的查询返回不正确的数据（我需要按季度排序）。我尝试为此使用模板，但没有帮助。

如果我不使用

.ceil

我有这样的排序数据。

1. 2023年1月11日
2. 2023/03/30
3. 2023/04/29
4. 2023/03/31
5. 2023/03/30
6. 2023/08/18

Answer 1

我现在看到了问题，我使用 your 日期在纯 Java 中做了一个演示。这是因为

java.time.Month

不是 零索引。运行以下命令并注意修正（减法，而不是四舍五入）使结果符合预期：

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Map;
import java.util.Comparator;
import java.util.Arrays;
import java.util.List;
import static java.util.stream.Collectors.*;

public class BirthdayQuartiles {
    record Birthday(String name, String date) {
        static DateTimeFormatter dtf = DateTimeFormatter.ofPattern("MM/dd/uuuu");
        final static String bformat = "%s : %s (%s)";
        LocalDate getAsLocalDate() {
            return LocalDate.parse(date, dtf);
        }
        @Override
        public String toString() {
            return bformat.formatted(name, date, getAsLocalDate().getMonth());
        }
    }
    public static void main(String[] args) throws Exception {
        Birthday[] birthdays = {
            new Birthday("Charles", "01/11/2023"),
            new Birthday("Diana", "03/30/2023"),
            new Birthday("Margaret", "04/29/2023"),
            new Birthday("Edward", "03/31/2023"),
            new Birthday("Beatrice", "03/30/2023"),
            new Birthday("William", "08/18/2023")
        };
        Map<Integer, List<Birthday>> quartiles = Arrays.stream(birthdays)
            .sorted(Comparator.comparing(Birthday::getAsLocalDate))
            // Adjust key as java.time.Month is NOT zero-indexed
            .collect(groupingBy(b ->(b.getAsLocalDate().getMonth().getValue()-1)/3, toList()));

        final String quartileFormat = "Birthday(s) in quartile %d: %s%n";
        quartiles.entrySet().stream()
            .forEach(e ->System.out.println(quartileFormat.formatted(e.getKey(), e.getValue())));  
    }
}