Using eval() to evaluate expressions stored in fields

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Alexey

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Feb 12, 2016, 1:05:12 PM2/12/16
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Hi,

I noticed that it's possible to use eval(<field>) instead of eval(<expression>) to evaluate an expression stored in <field> value. Although this is not mentioned in documentation, this feature is extremely useful in my case.

However, after running a small test case (bellow), I noticed that when having multiple records, the behavior is a bit odd. The expression appears to be only parsed once from whichever record comes first, and then evaluated for all records.

Is this a potential defect, or a performance decision? Are there any plans to support a more dynamic eval() with expressions in fields?

I am using latest OrientDB 2.1.10 GA Community Edition

Thanks.

========
Test Case:
========
orientdb {db=ylg-test1}> INFO CLASS TestClass1

CLASS 'TestClass1'

Super classes........: [V]
Default cluster......: testclass1 (id=30)
Supported clusters...: testclass1(30)
Cluster selection....: round-robin
Oversize.............: 0.0

PROPERTIES
-------------------------------+------------------+-------------------------------------+---------------------+------------------+----------------+-------------+-----------+----------------+
 NAME                     | TYPE          | LINKED TYPE/CLASS    | MANDATORY | READONLY | NOT NULL |    MIN    |  MAX    | COLLATE  |
-------------------------------+------------------+-------------------------------------+---------------------+------------------+----------------+-------------+-----------+----------------+
 b                             | STRING      | null                                | false               | false           | false          |              |             | default      |
 a                             | STRING      | null                                | false               | false           | false          |              |             | default      |
-------------------------------+------------------+------------------------------------+----------------------+------------------+----------------+-------------+-----------+----------------+

orientdb {db=ylg-test1}> SELECT a, b, eval(b) FROM TestClass1

----+-------------+----+--------------+----
#   |@CLASS|a   |b              |eval
----+-------------+----+--------------+----
0   |null         |5   |a + 3        |8
1   |null         |7   |3 + 2 + a  |10  <------- expected: 12
2   |null         |7   |3              |10 <------- expected: 3
----+-------------+----+--------------+----

3 item(s) found. Query executed in 0.01 sec(s).

user.w...@gmail.com

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Feb 13, 2016, 4:57:00 AM2/13/16
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Hi Alexey,

I tried your example and I have the same problem, I will let you know if I find something.

Regards,

Michela
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