Joda time issue with MySQL statement - mysql

Question

I'm using the Play Framework 2.1.2, the JDBC MySQL Connector and Scala 2.10. The following query is my problem:
DB.withConnection { implicit connection =>
SQL("""SELECT SUM(r.dayFrequency)
FROM relationships AS r
WHERE r.id = {id}
AND
(r.date BETWEEN {from} AND {to})""").on(
'id -> id,
'from -> from,
'to -> to).as(scalar[Int](bigDecimalToInt).single)
}
It raises this exception:
Execution exception[[RuntimeException: UnexpectedNullableFound(ColumnName(.SUM(r.dayFrequency),Some(SUM(r.dayFrequency))))]]
The console logs the following query:
SELECT SUM(r.dayFrequency)
FROM relationships AS r
WHERE r.id = 26180
AND
(r.date BETWEEN 2014-08-04 12:00:00.0 AND 2014-08-04 12:00:00.0)
If I run this query on my MySQL Workbench it returns null, which confirms the exception. But with this change in the query it works:
(r.date BETWEEN '2014-08-04' AND '2014-08-04')
For the conversion of Joda DateTime, I use this piece of code: Joda DateTime Field on Play Framework 2.0's Anorm
and frequency and date field looks like the following:
date DATE NOT NULL,
dayFrequency INT
Can anyone help with this problem? Seems that something is wrong with the conversion.
EDIT after first POST below:
From the view I receive date strings like this 2014-08-04 and I convert them into Joda DateTime in my controller to compare them to other and use them in MySQL queries like this:
private def clientDateStringToTimestamp(date: String) = {
val Array(year, month, day) = date.split("-")
new DateTime(year.toInt, month.toInt, day.toInt, 12, 0, 0).getMillis()
}
new DateTime(clientDateStringToTimestamp("2014-08-04"))
For the MySQL queries I want to compare only the date part not the time part.

Answer 1

So i did a simple experiment in mysql:
mysql> create table t (v int);
Query OK, 0 rows affected (0.01 sec)
mysql> insert into t values (null);
Query OK, 1 row affected (0.00 sec)
mysql> select sum(v) from t;
+--------+
| sum(v) |
+--------+
| NULL |
+--------+
1 row in set (0.01 sec)
mysql> insert into t values (1);
Query OK, 1 row affected (0.00 sec)
mysql> select sum(v) from t;
+--------+
| sum(v) |
+--------+
| 1 |
+--------+
1 row in set (0.00 sec)
mysql> update t set v = NULL;
Query OK, 1 row affected (0.00 sec)
Rows matched: 2 Changed: 1 Warnings: 0
mysql> select sum(v) from t;
+--------+
| sum(v) |
+--------+
| NULL |
+--------+
1 row in set (0.00 sec)
So this tells us that a summing nulls to nulls gives us null but summing nulls to numbers gives us numbers.
I suspect that your first query (r.date BETWEEN 2014-08-04 12:00:00.0 AND 2014-08-04 12:00:00.0) returns just rows with null dayFrequency values, where the second query (r.date BETWEEN '2014-08-04' AND '2014-08-04'), which is offset 12 hours earlier returns at least one non-null frequency. So since null is possible, you will have to use scalar[Option[Int]] for the sum, then turn it to 0 with getOrElse. A better way, if you can is to make the dayFrequency column in the database NOT NULL DEFAULT 0. Then it will give you a 0, and you can sum away

Answer 2

Also related, direct support for Joda temporal types in Anorm: https://github.com/playframework/playframework/commit/bdbbbe90822a6fb150c7044e68b33e2e52a7323d