Some Eclipse Foundation services are deprecated, or will be soon. Please ensure you've read this important communication.

Bug 350137

Summary:

[DB] [PostgreSQL] Exception when persisting EChar attribute with default '\u0000' value

Product:

[Modeling] EMF

Reporter:

Josh M <public.web.josh>

Component:

cdo.db

Assignee:

Eike Stepper <stepper>

Status:

CLOSED FIXED

QA Contact:

Eike Stepper <stepper>

Severity:

normal

Priority:

CC:

public.web.josh, stefan, stepper

Version:

4.2

Flags:

stepper: review+

Target Milestone:

---

Hardware:

All

OS:

All

Whiteboard:

Bug Depends on:

323006, 408479

Bug Blocks:

Attachments:

Description	Flags
Original exception and stack trace	none
patch-v1	none
Patch v2	none

Description Josh M

2011-06-23 08:47:00 EDT

Build Identifier: 20110218-0911

It seems that if the default value on an EChar attribute is not set, or if it is set to '\u0000' that CDO cannot persist the object due to an "invalid byte sequence for encoding 'UTF8': 0x00" error.  This may be specific to only a PostgreSQL datastore, but I am unable to test with other datastore implementations at this time. 

Details of this bug have been discussed in the forums: http://www.eclipse.org/forums/index.php/t/215023/

Reproducible: Always

Steps to Reproduce:
1. Configure PostgreSQL as the CDO datastore
2. Generate an ECore model with an object consisting of an EChar attribute.  Do not set its default attribute.
3. Instantiate the object with the EChar attribute, but do not change the EChar attribute's value.
4. Commit the object via CDO.

Comment 1 Josh M

2011-06-23 08:51:05 EDT

Created attachment 198465 [details]
Original exception and stack trace

Comment 2 Stefan Winkler

2011-06-23 12:56:31 EDT

The explanation seems to be easy:

Since the attribute is not unsettable, its default value is zero (0), because EChar reflects a base type (char).
Since the default type mapping represents a EChar or ECharacter as a String of length 1, it writes this string to the database.

PostgreSQL, however does not support NUL-characters in Strings: (e.g., see http://archives.postgresql.org/pgsql-jdbc/2007-02/msg00106.php)


The solution is more difficult.
In my opinion, the easiest way is to introduce a new type mapping, which maps EChar (and ECharacter) to a number field (instead a string field). I don't want to change the behavior of the existing type mapping, because of backwards-compatibility and because the string-representation is more 'direct'.

I'll have a look if the new TypeMapping can be configured transparently. (If not, a model annotation to use the correct type mapping would be needed).

Comment 3 Stefan Winkler

2011-06-25 12:36:51 EDT

Created attachment 198599 [details]
patch-v1

I have created a test case and a patch.
Introducing a char to integer mapping and setting the database type for char to integer for PostgreSQL fixes the problem. See attached patch.

Eike, please review.

Comment 4 Eike Stepper

2011-07-06 01:51:44 EDT

Created attachment 199160 [details]
Patch v2

Adjusted manifest version to 4.0.100.

Note that I'm going to move this bug/fix to 4.1!!!

Comment 5 Victor Roldan Betancort

2012-03-08 06:52:12 EST

More info here:

http://stackoverflow.com/questions/1347646/postgres-error-on-insert-error-invalid-byte-sequence-for-encoding-utf8-0x0

Comment 6 Victor Roldan Betancort

2012-03-08 07:23:19 EST

Guys, can we commit this fix? Fixes the issue nicely.

Comment 7 Eike Stepper

2012-08-14 22:56:36 EDT

Moving all open issues to 4.2. Open bugs can be ported to 4.1 maintenance after they've been fixed in master.

Comment 8 Eike Stepper

2012-10-31 06:20:29 EDT

Nothing in this patch applies to master anymore. Please reopen this bug if you feel a need.

Comment 9 Victor Roldan Betancort

2013-05-10 12:24:38 EDT

I managed to merge this old bug with master. Reopening for fixation

Comment 10 Eike Stepper

2013-05-20 06:08:39 EDT

I've provided a ColumnTypeModifier concept in bug 408479.

Comment 11 Eike Stepper

2013-05-20 06:15:26 EDT

I've taken the new EChar -> DBType.INTEGER type mappings and added a ColumnTypeModifier for Postgres. The attached test passes adn is committed:
commit aa8bfe023cad0c187cc2d88518456b1e8abf7828

Comment 12 Eike Stepper

2013-06-27 03:31:52 EDT

Available in R20130613-1157 (4.2)