Re: [pgAdmin4][Patch] - RM 3780 pgAdmin4 lacks ability to specifyNULL values in CSV export - Mailing list pgadmin-hackers

On Fri, Dec 21, 2018 at 2:08 PM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

On Fri, 21 Dec 2018, 18:52 Dave Page <dpage@pgadmin.org wrote:

Hi

Looks good - I just found one issue; please go ahead and commit (with a release notes update) when fixed.

- If I set the NULL replacement value to an empty string, it defaults back to NULL. It's therefore not possible to replace null values with an empty value.

    If you remember this is the default behaviour of the Preferences dialog. It sets the default value again if you set the blank value. Fahar has raised the same issue before and we have rejected that. If you think we can create the new RM for that behaviour and will commit the current patch.

Well, we rejected it for a specific case. In this specific case, it makes sense to be able to enter a blank value.

Maybe we just need an "allow blank" flag on the preference object, that does nothing except allow you to remove the default (or any other) value without it being replaced again? Obviously the default still needs to work until a value is written to the config DB. 

 

Thanks!

On Fri, Dec 21, 2018 at 12:57 PM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

I have modified the condition, it won't through any exception. Attached is the updated patch, please review it.

On Fri, Dec 21, 2018 at 4:22 AM Dave Page <dpage@pgadmin.org> wrote:

Sorry! Here is is.

On Fri, Dec 21, 2018 at 12:12 PM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

Can you please attached the updated patch with your changes. I'll try to fix the exception.

On Fri, Dec 21, 2018 at 3:57 AM Dave Page <dpage@pgadmin.org> wrote:

Hi

Here's an updated patch as I've tweaked some of the wording. The screenshot probably isn't the right resolution, but as we're replacing them anyway it doesn't seem overly important. Feel free to fix if you like :-)

With quoting set to either All or Strings, everything looks good. With it set to None, I still get an exception (below). The query I'm using is this:

SELECT NULL::text, 1234::int, 'Foo bar'::text, E'Foo\nBar'::text

Field separator: ,

Quote character: "

Replace null's with: NULL

Steps:

1) Run pgAdmin in Desktop mode. I'm running from within PyuCharms, using the venv detailed below.

2) Open the Query Tool on a PostgreSQL 9.6.10 database, running on MacOS 10.14.1

3) Run the above query, wit quoting set to All and check the result in the grid.

4) Download the CSV file and check.

5) Open Preferences and set quoting to Strings.

6) Download the CSV file and check.

7) Open Preferences and set quoting to None.

8) Download the CSV file *exception occurs*.

System info:

(pgadmin4) dpage@hal:~/git/pgadmin4$ python --version

Python 3.6.7

(pgadmin4) dpage@hal:~/git/pgadmin4$ pip freeze

alabaster==0.7.11

alembic==1.0.0

asn1crypto==0.24.0

Babel==2.6.0

bcrypt==3.1.4

blinker==1.4

certifi==2018.8.24

cffi==1.11.5

chardet==3.0.4

chromedriver-installer==0.0.6

click==6.7

cryptography==2.3

docutils==0.14

extras==1.0.0

fixtures==3.0.0

Flask==0.12.4

Flask-BabelEx==0.9.3

Flask-Gravatar==0.5.0

Flask-HTMLmin==1.3.2

Flask-Login==0.3.2

Flask-Mail==0.9.1

Flask-Migrate==2.1.1

Flask-Paranoid==0.2.0

Flask-Principal==0.4.0

Flask-Security==3.0.0

Flask-SQLAlchemy==2.3.2

Flask-WTF==0.14.2

html5lib==1.0.1

htmlmin==0.1.12

idna==2.7

imagesize==1.1.0

itsdangerous==0.24

Jinja2==2.10

linecache2==1.0.0

Mako==1.0.7

MarkupSafe==1.0

packaging==18.0

paramiko==2.4.1

passlib==1.7.1

pbr==3.1.1

psutil==5.4.8

psycopg2==2.7.5

pyasn1==0.4.4

pycodestyle==2.3.1

pycparser==2.18

pycrypto==2.6.1

Pygments==2.2.0

PyNaCl==1.2.1

pyparsing==2.2.2

pyperclip==1.6.4

pyrsistent==0.14.2

python-dateutil==2.7.3

python-editor==1.0.3

python-mimeparse==1.6.0

pytz==2018.3

requests==2.19.1

selenium==3.14.1

simplejson==3.13.2

six==1.11.0

snowballstemmer==1.2.1

speaklater==1.3

Sphinx==1.8.2

sphinxcontrib-websupport==1.1.0

SQLAlchemy==1.2.10

sqlparse==0.2.4

sshtunnel==0.1.4

testscenarios==0.5.0

testtools==2.3.0

traceback2==1.4.0

unittest2==1.1.0

urllib3==1.23

webencodings==0.5.1

Werkzeug==0.14.1

WTForms==2.1

Exception:

2018-12-21 11:47:28,995: SQL pgadmin: Execute (with server cursor) for server #2 - CONN:8760231 (Query-id: 8649354):

SELECT NULL::text, 1234::int, 'Foo bar'::text, E'Foo\nBar'::text

2018-12-21 11:47:29,001: INFO werkzeug: 127.0.0.1 - - [21/Dec/2018 11:47:29] "GET /sqleditor/query_tool/download/2133388?query=SELECT%20NULL%3A%3Atext%2C%201234%3A%3Aint%2C%20%27Foo%20bar%27%3A%3Atext%2C%20E%27Foo%5CnBar%27%3A%3Atext&filename=data-1545392848979.csv HTTP/1.1" 500 -

2018-12-21 11:47:29,003: ERROR werkzeug: Error on request:

Traceback (most recent call last):

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/serving.py", line 270, in run_wsgi

    execute(self.server.app)

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/serving.py", line 260, in execute

    for data in application_iter:

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/wsgi.py", line 870, in __next__

    return self._next()

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/wrappers.py", line 82, in _iter_encoded

    for item in iterable:

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/driver/psycopg2/connection.py", line 848, in gen

    csv_writer.writerows(results)

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 761, in writerows

    return self.writer.writerows(map(self._dict_to_list, rowdicts))

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 268, in writerows

    self.writerow(row)

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 261, in writerow

    row = [self.strategy.prepare(field, only=only) for field in row]

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 261, in <listcomp>

    row = [self.strategy.prepare(field, only=only) for field in row]

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 142, in prepare

    raise Error('No escapechar is set')

_csv.Error: No escapechar is set

On Thu, Dec 20, 2018 at 1:05 PM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

On Thu, Dec 20, 2018 at 5:12 PM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

On Thu, Dec 20, 2018 at 4:48 PM Dave Page <dpage@pgadmin.org> wrote:

Hi

On Thu, Dec 20, 2018 at 10:09 AM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

On Thu, Dec 20, 2018 at 3:08 PM Dave Page <dpage@pgadmin.org> wrote:

Hi

When testing with quoting set to None, quote = " and delimiter = , I get the following exception when I try to download:

2018-12-20 09:34:02,547: SQL pgadmin: Execute (with server cursor) for server #2 - CONN:354106 (Query-id: 4121147):

SELECT NULL::text, 1234::int, 'Foo bar'::text, E'Foo\nBar'::text

2018-12-20 09:34:02,570: INFO werkzeug: 127.0.0.1 - - [20/Dec/2018 09:34:02] "GET /sqleditor/query_tool/download/5610522?query=SELECT%20NULL%3A%3Atext%2C%201234%3A%3Aint%2C%20%27Foo%20bar%27%3A%3Atext%2C%20E%27Foo%5CnBar%27%3A%3Atext&filename=data-1545298442530.csv HTTP/1.1" 500 -

2018-12-20 09:34:02,572: ERROR werkzeug: Error on request:

Traceback (most recent call last):

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/serving.py", line 270, in run_wsgi

    execute(self.server.app)

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/serving.py", line 260, in execute

    for data in application_iter:

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/wsgi.py", line 870, in __next__

    return self._next()

  File "/Users/dpage/.virtualenvs/pgadmin4/lib/python3.6/site-packages/werkzeug/wrappers.py", line 82, in _iter_encoded

    for item in iterable:

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/driver/psycopg2/connection.py", line 820, in gen

    csv_writer.writerows(results)

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 748, in writerows

    return self.writer.writerows(map(self._dict_to_list, rowdicts))

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 256, in writerows

    self.writerow(row)

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 249, in writerow

    row = [self.strategy.prepare(field, only=only) for field in row]

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 249, in <listcomp>

    row = [self.strategy.prepare(field, only=only) for field in row]

  File "/Users/dpage/git/pgadmin4/web/pgadmin/utils/csv.py", line 136, in prepare

    raise Error('No escapechar is set')

_csv.Error: No escapechar is set

    Not able to reproduce the above issue. I have tested it with the same setting as you mentioned. Please refer all the attached screenshots. Please specify the steps if they are different.

When I have quoting set to All, the first column is returned as ""

dpage@hal:~/Downloads$ more data-1545298598112.csv 

"text","int4","text-2","text-3"

"","1234","Foo bar","Foo

Bar"

Isn't the point for it to be NULL?

    while quoting is set to ALL, all the data types has been quoted, so I thought null values should be replaced by "" instead of blank. But if you think null values shouldn't be quoted even if user select quote ALL, I'll fix it and resend the patch.

So how would you distinguish NULL from an empty string? Isn't that exactly what the bug is about?

I still think we need a "Replace NULLs with" config option, and regardless of quoting settings we always replace NULL values with whatever that is set to  - for which the user could then choose options like:

NULL

"NULL"

""

''

<empty string>

We would never quote the NULL replacement value - if the user wanted it to be quoted, they would include the quotes in the configured string.

   OK, Will work on it and send the modified patch again. 

      Attached is the modified patch as per your suggestion. 

 

On Tue, Dec 18, 2018 at 11:13 AM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

Attached is the modified patch to fix review comments.

On Tue, Dec 18, 2018 at 3:00 PM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

On Tue, Dec 18, 2018 at 2:49 PM Dave Page <dpage@pgadmin.org> wrote:

Hi

On Tue, Dec 18, 2018 at 3:45 AM Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Hackers,

Attached is the patch to fix RM #3780 pgAdmin4 lacks ability to specify NULL values in CSV export.

Please review it.

A few points;

- You've included code from backports.csv, but per the licence you need to include a description of the changes made.

      Sure. In that case I'll copy the complete file and will do my changes which is of two lines only. With my patch I have remove all the unwanted code from backport.csv.      

- Shouldn't backports.csv be removed from requirements.txt, or is it used elsewhere?

     Yes. Will do that. 

- If the previous point is true, then I'm fairly sure there is code in one or more of the many package build scripts that adds an __init__.py file to backports.csv in the venv that's created.

    I'll remove that code as well.  

 

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Akshay Joshi

Sr. Software Architect

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company