JDOQL / Java / GAE中按日期时间查询
我正在开发 GAE 应用程序。我想查询数据存储并检索开始日期和结束日期之间的所有记录。每条记录都有一个日期时间字段。我正在使用与此类似的查询（下面的代码是我快速抓取的代码 - 我不在我的开发机器附近。）：
Query query = pm.newQuery(Employee.class);
query.setFilter("lastName == lastNameParam");
query.setOrdering("hireDate desc");
query.declareParameters("String lastNameParam");
try {
List results = (List) query.execute("Smith");
if (results.iterator().hasNext()) {
for (Employee e : results) {
// ...
}
} else {
// ... no results ...
}
} finally {
query.closeAll();
}
我如何格式化日期以形成正确工作的查询？日期时间戳如何存储在数据存储中？作为时间戳？完全格式化了吗？我找不到这方面的任何信息。请帮忙。
I'm working on a GAE app. I want to query datastore and retrieve all records between startDate and endDate. Each record has a datetime field. I'm using a query similar to this (the below code is something I quickly grabbed - I'm not near my developer machine.):
Query query = pm.newQuery(Employee.class);
query.setFilter("lastName == lastNameParam");
query.setOrdering("hireDate desc");
query.declareParameters("String lastNameParam");
try {
List results = (List) query.execute("Smith");
if (results.iterator().hasNext()) {
for (Employee e : results) {
// ...
}
} else {
// ... no results ...
}
} finally {
query.closeAll();
}
How do I have to format the date to form a correctly working query? How is the datetime stamp stored in datastore? As timestamp? Fully formatted? I can't find ANY information on this. Please help.
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根据 google datastore 低级 API， 日期对象似乎可以在 GAE 中自由存储。因此，我认为使用 java.util.Date （或 javax.sql.Date，它并不完全明确）可以完成这项工作。
According to google datastore low-level API, Date Objects seems to be freely storable in GAE. As a consequence, using java.util.Date (or javax.sql.Date, it's not totally explicit) will do the job, i think.
您还可以使用时间戳
You can also use timestamp