Re: MySQL-ism help patch for psql

David Fetter just pointed this thread out to me. I think anything
that makes PostgreSQL more accessible could be a good thing. In some
sense it's harder to learn a technology when you are very familiar
with another similar one already. Is it easier to learn to type on
Dvorak, or to learn QWERTY and then switch to Dvorak? Switching was
harder for me than learning initially.

So I guess my advice, since David asked me :-) is not to underestimate
the pain of switching. I don't know whether this patch is the Right
Answer, but I think the sentiment is something to be encouraged. If
it's not the right answer, then maybe some brainstorming and user
input will reveal creative alternatives. I'll start:

== begin ==

Welcome to the POSTGRESQL interactive sql monitor:
Please read the file COPYRIGHT for copyright terms of POSTGRESQL

type \? for help on slash commands
type \mysql for a quick MySQL-to-PostgreSQL cheatsheet

somedb=> \mysql

psql uses backslash keywords instead of SHOW commands. There is
also a standard INFORMATION_SCHEMA if you're familiar with that.
The following commands might be helpful as you learn how to use psql:

Command in mysql Command in psql
================ ===============
SHOW TABLES \dt
DESCRIBE \d
... and so on.

== end ==

The full list of SHOW commands, should anyone be interested, is at
http://dev.mysql.com/doc/en/show.html

Cheers,
Baron

2010/1/24 Baron Schwartz <baron(at)xaprb(dot)com>:
> David Fetter just pointed this thread out to me.  I think anything
> that makes PostgreSQL more accessible could be a good thing.  In some
> sense it's harder to learn a technology when you are very familiar
> with another similar one already.  Is it easier to learn to type on
> Dvorak, or to learn QWERTY and then switch to Dvorak?  Switching was
> harder for me than learning initially.
>
> So I guess my advice, since David asked me :-) is not to underestimate
> the pain of switching.  I don't know whether this patch is the Right
> Answer, but I think the sentiment is something to be encouraged.  If
> it's not the right answer, then maybe some brainstorming and user
> input will reveal creative alternatives.  I'll start:

'psql --help mysql' (or 'psql --tips mysql' ) might be good to call a
special helper : I don't see the point to introduce that kind of
things when it is useless for most of our users. (so 'psql' won't
output any tips relative to mysql)

It offer then to have a 'psql --help oracle' or anyother special tips
we want to provide for our new users and following their knowledge.

And it will be able to provide usefull tips à la git for postgresql
regular users. (selcet --> did you mean select instead of selcet ?)

Regards,
Cédric

>
> == begin ==
>
> Welcome to the POSTGRESQL interactive sql monitor:
>  Please read the file COPYRIGHT for copyright terms of POSTGRESQL
>
>   type \? for help on slash commands
>   type \mysql for a quick MySQL-to-PostgreSQL cheatsheet
>
> somedb=> \mysql
>
> psql uses backslash keywords instead of SHOW commands.  There is
> also a standard INFORMATION_SCHEMA if you're familiar with that.
> The following commands might be helpful as you learn how to use psql:
>
>  Command in mysql  Command in psql
>  ================  ===============
>  SHOW TABLES       \dt
>  DESCRIBE          \d
>  ... and so on.
>
> == end ==
>
> The full list of SHOW commands, should anyone be interested, is at
> http://dev.mysql.com/doc/en/show.html
>
> Cheers,
> Baron
>
> --
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>

--
Cédric Villemain

Hi Cédric,

On Sun, Jan 24, 2010 at 5:11 PM, Cédric Villemain
<cedric(dot)villemain(dot)debian(at)gmail(dot)com> wrote:
> 'psql --help mysql' (or 'psql --tips mysql' ) might be good to call a
> special helper : I don't see the point to introduce that kind of
> things when it is useless for most of our users.

I think it's good to go beyond what's useful for most users. It's
good to help potential users, too.

- Baron

2010/1/25 Baron Schwartz <baron(at)xaprb(dot)com>:
> Hi Cédric,
>
> On Sun, Jan 24, 2010 at 5:11 PM, Cédric Villemain
> <cedric(dot)villemain(dot)debian(at)gmail(dot)com> wrote:
>> 'psql --help mysql' (or 'psql --tips mysql' ) might be good to call a
>> special helper : I don't see the point to introduce that kind of
>> things when it is useless for most of our users.
>
> I think it's good to go beyond what's useful for most users.  It's
> good to help potential users, too.

Absolutly, that's why I suggest to give a simple option to activate
those helpers.
We didn't remove extra lines on the psql login to add anothers now.

--
Cédric Villemain

If this option is designed to help people's transition - basically to
get to them before they've got to most of the manual - having to turn
it on will be pointless. It needs to be active by default. A way to
avoid it being a default option in psql may be setting an alias as
part of package installation so power users couid turn it off by
without having to add a switch to their command lines. It's not going
to have anything to say to experienced psql users anyway so it would
probably not bug anyone enough to turn it off.

Regards

Alastair

On Mon, Jan 25, 2010 at 5:46 PM, Cédric Villemain
<cedric(dot)villemain(dot)debian(at)gmail(dot)com> wrote:
> 2010/1/25 Baron Schwartz <baron(at)xaprb(dot)com>:
>> Hi Cédric,
>>
>> On Sun, Jan 24, 2010 at 5:11 PM, Cédric Villemain
>> <cedric(dot)villemain(dot)debian(at)gmail(dot)com> wrote:
>>> 'psql --help mysql' (or 'psql --tips mysql' ) might be good to call a
>>> special helper : I don't see the point to introduce that kind of
>>> things when it is useless for most of our users.
>>
>> I think it's good to go beyond what's useful for most users.  It's
>> good to help potential users, too.
>
> Absolutly, that's why I suggest to give a simple option to activate
> those helpers.
> We didn't remove extra lines on the psql login to add anothers now.
>
> --
> Cédric Villemain
>
> --
> Sent via pgsql-hackers mailing list (pgsql-hackers(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-hackers
>

* Alastair Bell Turner <thebellhead(at)gmail(dot)com> [100125 11:07]:
> If this option is designed to help people's transition - basically to
> get to them before they've got to most of the manual - having to turn
> it on will be pointless. It needs to be active by default. A way to
> avoid it being a default option in psql may be setting an alias as
> part of package installation so power users couid turn it off by
> without having to add a switch to their command lines. It's not going
> to have anything to say to experienced psql users anyway so it would
> probably not bug anyone enough to turn it off.

I'ld be more comfortable for a line in t the more standard help along
the lines of:
"For more information on PSQL commands when coming from other
databases, see the documentation."

And then we can have a full discussion in the docs, psql man page,
wherever, where you can actually *describe* the differences between the
commands, etc, instead of loosing the useful information because of
trying to stuff things into a 1-line message about something that might
not have been intended...

And then you can have a section on MySQL, SQLite, DB2, Informix,
Firebird, Oracle, etc... Basically a section for whoever has an itch.

a.

--
Aidan Van Dyk Create like a god,
aidan(at)highrise(dot)ca command like a king,
http://www.highrise.ca/ work like a slave.

Alastair "Bell" Turner wrote:
> If this option is designed to help people's transition - basically to
> get to them before they've got to most of the manual - having to turn
> it on will be pointless. It needs to be active by default.
>

My problem with this whole idea is that it seems to be very
MySQL-specific. Why aren't we providing help for users migrating from
Oracle, Sybase, Informix, Ingres, DB2, SQLServer and Firebird, to name
but a few? And if we turn all those on by default, we'll have a pretty
horrible banner when starting psql.

cheers

andrew

On Mon, Jan 25, 2010 at 6:14 PM, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
>
> My problem with this whole idea is that it seems to be very MySQL-specific.
> Why aren't we providing help for users migrating from Oracle, Sybase,
> Informix, Ingres, DB2, SQLServer and Firebird, to name but a few? And if we
> turn all those on by default, we'll have a pretty horrible banner when
> starting psql.
>
> cheers
>
> andrew
>
The easy way around that would be a message along the lines of '
\migrate for information on how the commands from your previous
environment translate to psql' It's a bit verbose but could be trimmed
I'm sure.

The \migrate mysql, \migrate db2, \migrate ingres ... could all do
their own thing. Some of the command specific responses won't be
extened too much either since DESCRIBE and SHOW apply in multiple
places similarly enough that the one line reminder could be
interchangable.

On Mon, Jan 25, 2010 at 11:14 AM, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
> Alastair "Bell" Turner wrote:
>>
>> If this option is designed to help people's transition - basically to
>> get to them before they've got to most of the manual - having to turn
>> it on will be pointless. It needs to be active by default.
>
> My problem with this whole idea is that it seems to be very MySQL-specific.
> Why aren't we providing help for users migrating from Oracle, Sybase,
> Informix, Ingres, DB2, SQLServer and Firebird, to name but a few? And if we
> turn all those on by default, we'll have a pretty horrible banner when
> starting psql.

I don't really have a horse in this race, but perhaps the answer is
that people are asking for MySQL help but no one is asking for help
migrating from any of those other databases. At least not yet. But I
think we're getting off into the weeds a little bit here. In theory,
people who notice that psql gives the following message should be OK:

Type "help" for help.

Now when you type help, you get this:

You are using psql, the command-line interface to PostgreSQL.
Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit

Now, at this point, if you are a MySQL user who wants to find the
equivalent of SHOW TABLES and DESCRIBE, it's very plausible that
you'll now try \h, because SHOW TABLES and DESCRIBE are SQL commands.
Then you might try some things like:

\h SHOW
\h TABLE

...hoping to find what you're looking for. If you eventually go back
and try \? you will hopefully notice this line (which at least in my
terminal window doesn't even show up until the second page):

\d[S+] list tables, views, and sequences

It's not too much to hope that you'll try \d at this point and get a
list of all your tables, but it's far from clear how you'd know that
"\d foo" is the way to get the column definitions for foo.

Maybe instead of (or in addition to) providing MySQL-specific help, we
should find a way to emphasize the "\d" and "\d table" commands,
because those are (IMO) two big things that people coming from ANY
other database product are likely to want to find, and it's not as
easy to find them right now as perhaps it should be.

...Robert

On Mon, Jan 25, 2010 at 06:06:53PM +0200, Alastair Bell Turner wrote:
<..>
> without having to add a switch to their command lines. It's not going
> to have anything to say to experienced psql users anyway so it would
> probably not bug anyone enough to turn it off.

I would so use this feature going the other way: fire up comfortable
psql and see what mysql command I need to type ... Having it in the
interface (behind \help [mysql|oracle|firebird|mssql|..] seems reasonable
to me, given how much info we already have in \help. I find the basic
BNF help for SQL syntax still useful reminder, and know to go to the
actual docs when there's not enough there. So a quick mapping of
most-needed commands, and a pointer to the docs for the full
ramifications and subtle differences seems to fit the existing
documentation module.

Ross
--
Ross Reedstrom, Ph.D. reedstrm(at)rice(dot)edu
Systems Engineer & Admin, Research Scientist phone: 713-348-6166
The Connexions Project http://cnx.org fax: 713-348-3665
Rice University MS-375, Houston, TX 77005
GPG Key fingerprint = F023 82C8 9B0E 2CC6 0D8E F888 D3AE 810E 88F0 BEDE

On Mon, Jan 25, 2010 at 10:49:55AM -0600, Ross J. Reedstrom wrote:
> On Mon, Jan 25, 2010 at 06:06:53PM +0200, Alastair Bell Turner wrote:
> <..>
> > without having to add a switch to their command lines. It's not going
> > to have anything to say to experienced psql users anyway so it would
> > probably not bug anyone enough to turn it off.
>
> I would so use this feature going the other way: fire up comfortable
> psql and see what mysql command I need to type ... Having it in the
> interface (behind \help [mysql|oracle|firebird|mssql|..] seems reasonable
> to me, given how much info we already have in \help. I find the basic

> BNF help for SQL syntax still useful reminder, and know to go to the

Well, behind \migrate or some other word as others have, since I see
\help is just the SQL help I so praised.

Ross
--
Ross Reedstrom, Ph.D. reedstrm(at)rice(dot)edu
Systems Engineer & Admin, Research Scientist phone: 713-348-6166
The Connexions Project http://cnx.org fax: 713-348-3665
Rice University MS-375, Houston, TX 77005
GPG Key fingerprint = F023 82C8 9B0E 2CC6 0D8E F888 D3AE 810E 88F0 BEDE

Ross J. Reedstrom wrote:
> So a quick mapping of most-needed commands, and a pointer to the docs for the full
> ramifications and subtle differences seems to fit the existing
> documentation module.
>

And that's been done at least twice already:

http://blog.endpoint.com/2009/12/mysql-and-postgres-command-equivalents.html
http://en.wikibooks.org/wiki/Converting_MySQL_to_PostgreSQL

--
Greg Smith 2ndQuadrant Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.com

Ross J. Reedstrom wrote:
> On Mon, Jan 25, 2010 at 06:06:53PM +0200, Alastair Bell Turner wrote:
> <..>
> > without having to add a switch to their command lines. It's not going
> > to have anything to say to experienced psql users anyway so it would
> > probably not bug anyone enough to turn it off.
>
> I would so use this feature going the other way: fire up comfortable
> psql and see what mysql command I need to type ... Having it in the
> interface (behind \help [mysql|oracle|firebird|mssql|..] seems reasonable
> to me, given how much info we already have in \help. I find the basic
> BNF help for SQL syntax still useful reminder, and know to go to the
> actual docs when there's not enough there. So a quick mapping of
> most-needed commands, and a pointer to the docs for the full
> ramifications and subtle differences seems to fit the existing
> documentation module.

It would be interesting to implement \help mysql, and then have commands
like SHOW TABLE trigger a message suggesting they do \help mysql.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +

Hi Robert,

On Mon, Jan 25, 2010 at 11:41 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> Maybe instead of (or in addition to) providing MySQL-specific help, we
> should find a way to emphasize the "\d" and "\d table" commands,

Right, it's like "cd" and "ls" at the shell prompt. It's like walking
into a dark room and not knowing where the light switch is. I'll
think of more metaphors later.

What if the text you see upon starting psql says something like "Type
\dt to ... type \h for more help" ?

On Mon, Jan 25, 2010 at 1:05 PM, Baron Schwartz <baron(at)xaprb(dot)com> wrote:
> Hi Robert,
>
> On Mon, Jan 25, 2010 at 11:41 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> Maybe instead of (or in addition to) providing MySQL-specific help, we
>> should find a way to emphasize the "\d" and "\d table" commands,
>
> Right, it's like "cd" and "ls" at the shell prompt.  It's like walking
> into a dark room and not knowing where the light switch is.  I'll
> think of more metaphors later.
>
> What if the text you see upon starting psql says something like "Type
> \dt to ... type \h for more help" ?

Well, we used to display this banner when psql started up:

Welcome to psql 8.3.8, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit

But it got changed, so now it just tells you to type help and if you
do then you get that banner. But maybe that's OK. Since the banner
isn't being printed on every startup, it might be OK for it to be a
bit longer, like, I dunno:

Type: \copyright for distribution terms
\h for help with SQL commands
\d for a list of tables, views, and sequences in the current database
\d name for more details on the named table, view, index, or sequence
\? for further help with psql commands
\g or terminate with semicolon to execute query
\q to quit

That might be just enough of a push to get people pointed in the right
direction.

...Robert

>> My problem with this whole idea is that it seems to be very MySQL-specific.
>> Why aren't we providing help for users migrating from Oracle, Sybase,
>> Informix, Ingres, DB2, SQLServer and Firebird, to name but a few? And if we
>> turn all those on by default, we'll have a pretty horrible banner when
>> starting psql.

We should do all of those. However, we have to start somewhere.

Therefore, I like the idea of having a switch, like:
\advice mysql
\advice db2
etc.

ALSO, I'll point out that a page in our official documentation with
extensive docs on commands and migration issues would be far more
helpful than any amount of psql messages. Just sayin'.

--Josh Berkus

Josh,

On Mon, Jan 25, 2010 at 1:47 PM, Josh Berkus <josh(at)agliodbs(dot)com> wrote:
>
>>> My problem with this whole idea is that it seems to be very MySQL-specific.
>>> Why aren't we providing help for users migrating from Oracle, Sybase,
>>> Informix, Ingres, DB2, SQLServer and Firebird, to name but a few? And if we
>>> turn all those on by default, we'll have a pretty horrible banner when
>>> starting psql.
>
> We should do all of those.  However, we have to start somewhere.
>
> Therefore, I like the idea of having a switch, like:
> \advice mysql
> \advice db2
> etc.
>
> ALSO, I'll point out that a page in our official documentation with
> extensive docs on commands and migration issues would be far more
> helpful than any amount of psql messages.  Just sayin'.

Hypothetically, if I had time to help with something like that, is
there a wiki or something where I could help draft it, without needing
to get all elbows-deep into the documentation itself?

Baron

Baron,

> Hypothetically, if I had time to help with something like that, is
> there a wiki or something where I could help draft it, without needing
> to get all elbows-deep into the documentation itself?

wiki.postgresql.org.

--Josh

Josh Berkus wrote:
>
> >> My problem with this whole idea is that it seems to be very MySQL-specific.
> >> Why aren't we providing help for users migrating from Oracle, Sybase,
> >> Informix, Ingres, DB2, SQLServer and Firebird, to name but a few? And if we
> >> turn all those on by default, we'll have a pretty horrible banner when
> >> starting psql.
>
> We should do all of those. However, we have to start somewhere.
>
> Therefore, I like the idea of having a switch, like:
> \advice mysql
> \advice db2
> etc.
>
> ALSO, I'll point out that a page in our official documentation with
> extensive docs on commands and migration issues would be far more
> helpful than any amount of psql messages. Just sayin'.

I don't think we came to any firm conclusion in this thread, so I have
added a TODO item:

Add option to print advice for people familiar with other databases

* http://archives.postgresql.org/pgsql-hackers/2010-01/msg01845.php

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +