Simple Question: How to get current date in Java to be used in GQL query?

Question

I have a Users table that has an element called "date". I would like to make these pseudocode queries work in Java:

select * from Users WHERE date=today

and also

select * from Users WHERE date "in this hour"

How can I write the queries?

I am using Google App Engine, and the date was initially created using java.util.Date.

Please help. Thanks

Jay Askren · Answer 1 · 2010-01-20T06:13:58.380

1

Since a date in GoogleAppEngine specifies time down to the millisecond using "=" will not likely work.

It appears you could do something like the following:

select from Users where date >= midnightWesnesday
                      && date < midnightThusday;

You should also be able to specify the correct range for the hour accordingly.

edited Jan 20 '10 at 06:13

answered Jan 20 '10 at 05:43

Jay Askren

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jspcal · Answer 2 · 2010-01-20T18:07:24.610

0

PreparedStatement st = conn.prepareStatement("select * from Users where date = ?");
st.setDate(1, new java.sql.Date(System.currentMillis());
ResultSet rs = st.executeQuery();

jiql is a Java JDBC wrapper for Cloud computing databases. The database is accessed via the jiql jdbc client. The data is actually stored in a cloud-based data store, such as Google's BigTable.

http://www.jiql.org/xwiki/bin/view/Main/

edited Jan 20 '10 at 18:07

answered Jan 20 '10 at 05:40

jspcal

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You cannot use JDBC on App Engine. – Thilo Jan 20 '10 at 05:47
@Thilo, those classes are whitelisted: http://code.google.com/appengine/docs/java/jrewhitelist.html – jspcal Jan 20 '10 at 05:51
@Thilo, its pretty nice they actually work. it's useful so you can re-use existing code (check out jiql) – jspcal Jan 20 '10 at 18:09
Okay, with the interesting link to jiql, this answer makes sense. Not sure how valid this approach is though... – Thilo Jan 20 '10 at 23:55

Simple Question: How to get current date in Java to be used in GQL query?

2 Answers2