Java 使用 JPA Criteria Query 比较两个日期之间的差异
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Compare difference between two dates using JPA Criteria Query
提问by Ashvin Kanani
I am using MySQL as a backend for my application.
我使用 MySQL 作为我的应用程序的后端。
I want to execute query below using JPA Criteria Query.
我想使用 JPA Criteria Query 在下面执行查询。
SELECT *
FROM table1 t1
WHERE datediff(now(), t1.created) >= 20;
Note: Type of createdis TIMESTAMP
注意：类型created是TIMESTAMP
I want Criteria Query like:
我想要标准查询，如：
CriteriaBuilder cb = getEntityManager().getCriteriaBuilder();
// select
CriteriaQuery<Table1> query = cb.createQuery(Table1.class);
// from
Root<Table1> root = query.from(Table1.class);
// where
List<Predicate> predicates = new ArrayList<Predicate>();
// TODO: add expression for datediff(now(), t1.created) >= 20
query.where(cb.and(predicates.toArray(new Predicate[0])));
Can any one help?
任何人都可以帮忙吗？
Thanks in advance.
提前致谢。
采纳答案by perissf
Supposing that createdis a java.util.Date, you have to perform the DATEDIFFin java and compare the property with the resulting date:
假设这created是 a java.util.Date，您必须DATEDIFF在 java 中执行并将该属性与结果日期进行比较：
Calendar c = Calendar.getInstance();
c.add(Calendar.DAY_OF_YEAR, -20);
Date myDate = c.getTime();
predicates.add(cb.lessThanOrEqualTo(root.<Date>get("created"), myDate));
