Обсуждение: How to copy a schema under another name in same database

Hi Daniel,

Actually not 100% sure if this works the same for Postgres but I always
did the following in Sybase:

select * into newtabel from oldtable where 1=2

Creates a duplicate of oldtable but without the data (remove the where
if you want the data to be copied aswell). You still need to recreate
the indexes if those are needed off course.

--
Kindest Regards,

Bastiaan Olij
e-mail/MSN: bastiaan@basenlily.nl
web: http://www.basenlily.nl
Skype: Mux213
http://www.linkedin.com/in/bastiaanolij



Daniel Gour wrote:
>
> Hello! I have a PostgreSQL (8.3.3, WinXP + linux) database with
> multiple schemas. I would like, on a regular basis, to be able to copy
> the structure and data of one schema under a new schema, using of
> course a different name. What would be the easiest way?
>
> - I have seen the TODO entry “Add CREATE SCHEMA ... LIKE that copies a
> schema”, so I guess an easy solution (a single pgsql command) is not
> yet available…
>
> - I guess the alternative is to use pg_dump to dump a single schema
> and use pg_restore, but how can I restore the dumped information under
> another schema? I would like to avoid dumping it as an sql script and
> having it to modify it manually, because this will be a regular
> operation that I would like to automate in my application.
>
> Thanks in advance for any insight you can provide!
>
> ---------------------------------
> Daniel Gour
> Adacel Inc.
>

Never had a need for this.  One thought that comes to mind write a
plpgsql function that takes in name of new schema and old schema and
does something like below

--Create new tables in new schema

FOR tbltocopy IN(SELECT table_name 
                FROM information_schema.tables 
                WHERE table_type = 'BASE TABLE' AND
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE TABLE ' || param_dest_schema || '.' || tbltocopy
|| '( LIKE ' || param_source_schema || '.' || tbltocopy || ' INCLUDING
DEFAULT CONSTRAINTS INDEXES '); 
INSERT INTO ' || param_dest_schema || '.' || tbltocopy || ' SELECT *
FROM ' param_source_schema || '.' || tbltocopy || ';');

NEXT;


Hope that helps,
Regina



-----Original Message-----
From: pgsql-novice-owner@postgresql.org on behalf of Daniel Gour
Sent: Tue 7/29/2008 9:20 AM
To: pgsql-novice@postgresql.org
Subject: [NOVICE] How to copy a schema under another name in same
database
 
Hello!  I have a PostgreSQL (8.3.3, WinXP + linux) database with
multiple
schemas.  I would like, on a regular basis, to be able to copy the
structure
and data of one schema under a new schema, using of course a different
name.
What would be the easiest way?

 

-          I have seen the TODO entry "Add CREATE SCHEMA ... LIKE that
copies
a schema", so I guess an easy solution (a single pgsql command) is not
yet
available...

 

-          I guess the alternative is to use pg_dump to dump a single
schema
and use pg_restore, but how can I restore the dumped information under
another schema?  I would like to avoid dumping it as an sql script and
having
it to modify it manually, because this will be a regular operation that
I
would like to automate in my application.

 

Thanks in advance for any insight you can provide!

---------------------------------
Daniel Gour
Adacel Inc.



 


-----------------------------------------
The substance of this message, including any attachments, may be
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contact the sender and delete the material from any computer.

Thank you for your input, but I was looking for was a solution to copy all of
the database objects (table, indexes, functions, etc) (and their data) that
are under one schema and copy them into another schema.

For your info, your suggested command works well under PostgreSQL as well.

Thanks again!

---------------------------------
Daniel Gour, Eng.
SPT/IOS/DB CSCI Lead

-----Original Message-----
From: Bastiaan Olij [mailto:lists@basenlily.nl]
Sent: Tuesday, July 29, 2008 7:06 PM
To: Daniel Gour
Cc: pgsql-novice@postgresql.org
Subject: Re: [NOVICE] How to copy a schema under another name in same
database

Hi Daniel,

Actually not 100% sure if this works the same for Postgres but I always
did the following in Sybase:

select * into newtabel from oldtable where 1=2

Creates a duplicate of oldtable but without the data (remove the where
if you want the data to be copied aswell). You still need to recreate
the indexes if those are needed off course.

--
Kindest Regards,

Bastiaan Olij
e-mail/MSN: bastiaan@basenlily.nl
web: http://www.basenlily.nl
Skype: Mux213
http://www.linkedin.com/in/bastiaanolij



Daniel Gour wrote:
>
> Hello! I have a PostgreSQL (8.3.3, WinXP + linux) database with
> multiple schemas. I would like, on a regular basis, to be able to copy
> the structure and data of one schema under a new schema, using of
> course a different name. What would be the easiest way?
>
> - I have seen the TODO entry "Add CREATE SCHEMA ... LIKE that copies a
> schema", so I guess an easy solution (a single pgsql command) is not
> yet available...
>
> - I guess the alternative is to use pg_dump to dump a single schema
> and use pg_restore, but how can I restore the dumped information under
> another schema? I would like to avoid dumping it as an sql script and
> having it to modify it manually, because this will be a regular
> operation that I would like to automate in my application.
>
> Thanks in advance for any insight you can provide!
>
> ---------------------------------
> Daniel Gour
> Adacel Inc.
>

Thanks for the information!  That looks promising, I will attempt to
implement it this week and let you know.

---------------------------------
Daniel Gour
Adacel Inc.

-----Original Message-----
From: Obe, Regina [mailto:robe.dnd@cityofboston.gov]
Sent: Wednesday, July 30, 2008 7:14 AM
To: Daniel Gour; pgsql-novice@postgresql.org
Subject: RE: [NOVICE] How to copy a schema under another name in same
database

Never had a need for this.  One thought that comes to mind write a
plpgsql function that takes in name of new schema and old schema and
does something like below

--Create new tables in new schema

FOR tbltocopy IN(SELECT table_name
                FROM information_schema.tables
                WHERE table_type = 'BASE TABLE' AND
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE TABLE ' || param_dest_schema || '.' || tbltocopy
|| '( LIKE ' || param_source_schema || '.' || tbltocopy || ' INCLUDING
DEFAULT CONSTRAINTS INDEXES ');
INSERT INTO ' || param_dest_schema || '.' || tbltocopy || ' SELECT *
FROM ' param_source_schema || '.' || tbltocopy || ';');

NEXT;


Hope that helps,
Regina



-----Original Message-----
From: pgsql-novice-owner@postgresql.org on behalf of Daniel Gour
Sent: Tue 7/29/2008 9:20 AM
To: pgsql-novice@postgresql.org
Subject: [NOVICE] How to copy a schema under another name in same
database

Hello!  I have a PostgreSQL (8.3.3, WinXP + linux) database with
multiple
schemas.  I would like, on a regular basis, to be able to copy the
structure
and data of one schema under a new schema, using of course a different
name.
What would be the easiest way?



-          I have seen the TODO entry "Add CREATE SCHEMA ... LIKE that
copies
a schema", so I guess an easy solution (a single pgsql command) is not
yet
available...



-          I guess the alternative is to use pg_dump to dump a single
schema
and use pg_restore, but how can I restore the dumped information under
another schema?  I would like to avoid dumping it as an sql script and
having
it to modify it manually, because this will be a regular operation that
I
would like to automate in my application.



Thanks in advance for any insight you can provide!

---------------------------------
Daniel Gour
Adacel Inc.






-----------------------------------------
The substance of this message, including any attachments, may be
confidential, legally privileged and/or exempt from disclosure
pursuant to Massachusetts law. It is intended
solely for the addressee. If you received this in error, please
contact the sender and delete the material from any computer.

Daniel,

I had a typo in the below that I just noticed.  Should be I think - but
I'm sure I screwed up in other ways, but hopefully you get the idea.


FOR tbltocopy IN(SELECT table_name
                FROM information_schema.tables
                WHERE table_type = 'BASE TABLE' AND
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE TABLE ' || param_dest_schema || '.' || tbltocopy
|| '( LIKE ' || param_source_schema || '.' || tbltocopy || ' INCLUDING
DEFAULT CONSTRAINTS INDEXES );
INSERT INTO ' || param_dest_schema || '.' || tbltocopy || ' SELECT *
FROM ' param_source_schema || '.' || tbltocopy || ';');

If you need to copy views as well, that's a bit trickier since I assume
you would want your views to reference the specific schema objects
within the destination schema not the source schema.

For that take a look at information_schema.views  -- it has a field
called view_definition.

You could use that to build the view and then macro replace the
references to the schema with the new schema I guess.

Something like
DECLARE vwdef information_schema.views  --this part is iffy not sure if
a type is created for information_schema stuff

FOR vwdef IN(SELECT *
                FROM information_schema.views
                WHERE
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE VIEW ' || param_dest_schema || '.' ||
vwdef.table_name
|| '( AS ' || REPLACE(vwdef.view_definition, param_source_schema || '.',
param_dest_schema || '.')
|| ';');

Hope that helps,
Regina

-----Original Message-----
From: Daniel Gour [mailto:Daniel.Gour@adacel.com]
Sent: Wednesday, July 30, 2008 9:12 AM
To: Obe, Regina
Cc: pgsql-novice@postgresql.org
Subject: RE: [NOVICE] How to copy a schema under another name in same
database

Thanks for the information!  That looks promising, I will attempt to
implement it this week and let you know.

---------------------------------
Daniel Gour
Adacel Inc.

-----Original Message-----
From: Obe, Regina [mailto:robe.dnd@cityofboston.gov]
Sent: Wednesday, July 30, 2008 7:14 AM
To: Daniel Gour; pgsql-novice@postgresql.org
Subject: RE: [NOVICE] How to copy a schema under another name in same
database

Never had a need for this.  One thought that comes to mind write a
plpgsql function that takes in name of new schema and old schema and
does something like below

--Create new tables in new schema

FOR tbltocopy IN(SELECT table_name
                FROM information_schema.tables
                WHERE table_type = 'BASE TABLE' AND
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE TABLE ' || param_dest_schema || '.' || tbltocopy
|| '( LIKE ' || param_source_schema || '.' || tbltocopy || ' INCLUDING
DEFAULT CONSTRAINTS INDEXES ');
INSERT INTO ' || param_dest_schema || '.' || tbltocopy || ' SELECT *
FROM ' param_source_schema || '.' || tbltocopy || ';');

NEXT;


Hope that helps,
Regina



-----Original Message-----
From: pgsql-novice-owner@postgresql.org on behalf of Daniel Gour
Sent: Tue 7/29/2008 9:20 AM
To: pgsql-novice@postgresql.org
Subject: [NOVICE] How to copy a schema under another name in same
database

Hello!  I have a PostgreSQL (8.3.3, WinXP + linux) database with
multiple
schemas.  I would like, on a regular basis, to be able to copy the
structure
and data of one schema under a new schema, using of course a different
name.
What would be the easiest way?



-          I have seen the TODO entry "Add CREATE SCHEMA ... LIKE that
copies
a schema", so I guess an easy solution (a single pgsql command) is not
yet
available...



-          I guess the alternative is to use pg_dump to dump a single
schema
and use pg_restore, but how can I restore the dumped information under
another schema?  I would like to avoid dumping it as an sql script and
having
it to modify it manually, because this will be a regular operation that
I
would like to automate in my application.



Thanks in advance for any insight you can provide!

---------------------------------
Daniel Gour
Adacel Inc.






-----------------------------------------
The substance of this message, including any attachments, may be
confidential, legally privileged and/or exempt from disclosure
pursuant to Massachusetts law. It is intended
solely for the addressee. If you received this in error, please
contact the sender and delete the material from any computer.

Daniel Gour wrote:
> Hello!  I have a PostgreSQL (8.3.3, WinXP + linux) database with
> multiple schemas.  I would like, on a regular basis, to be able to copy
> the structure and data of one schema under a new schema, using of course
> a different name.  What would be the easiest way?



Backup the schema with pg_dump; edit file; change schema name and
restore?  If schema names do not show up in data; then this might work:

pg_dump ... | sed s:schema1:schema2:g | psql

Thanks for the suggestion, but I need the application to be multi-platform
(I'm using Qt).  Since sed is not natively available on XP...  Also, as you
mention, it is risky to blindly replace one string for another in the whole
sql script.

The solution is however simple and elegant, maybe someone else will find it
useful.  Thanks!

---------------------------------
Daniel Gour
Adacel Inc.

-----Original Message-----
From: Frank Bax [mailto:fbax@sympatico.ca]
Sent: Wednesday, July 30, 2008 12:51 PM
To: PostgreSQL List - Novice
Subject: Re: [NOVICE] How to copy a schema under another name in same
database

Daniel Gour wrote:
> Hello!  I have a PostgreSQL (8.3.3, WinXP + linux) database with
> multiple schemas.  I would like, on a regular basis, to be able to copy
> the structure and data of one schema under a new schema, using of course
> a different name.  What would be the easiest way?



Backup the schema with pg_dump; edit file; change schema name and
restore?  If schema names do not show up in data; then this might work:

pg_dump ... | sed s:schema1:schema2:g | psql


--
Sent via pgsql-novice mailing list (pgsql-novice@postgresql.org)
To make changes to your subscription:
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On Wed, Jul 30, 2008 at 12:04 PM, Daniel Gour <Daniel.Gour@adacel.com> wrote:
> Thanks for the suggestion, but I need the application to be multi-platform
> (I'm using Qt).  Since sed is not natively available on XP...

Check out UnxUtils, it includes sed and friends:
http://sourceforge.net/project/showfiles.php?group_id=9328

Good luck.

"Rob Richardson" <Rob.Richardson@rad-con.com> writes:
> In the help file under date and time functions, I see that intervals can be specified as "interval '3 hours' ".  In a
PgAdminSQL window, I can enter "select interval '3 hours' ", and it will return me "03:00:00", as expected.  I can also
enter"select '3 hours'::interval", and get the same result.  Yet neither syntax works inside a function.   

> declare
>      ThreeHours interval;
> begin
>      ThreeHours = interval '3 hours';  -- throws a syntax error
>      ThreeHours = '3 hours'::interval; -- also throws a syntax error
> end;

Either of those should work.  I think your problem is that you're not
quoting the whole function body correctly.  Remember that the function
body is itself a string constant.  So if you were to try to write this
as a single-quoted string, you'd need to double those embedded quotes:

CREATE FUNCTION ... AS '
declare
     ThreeHours interval;
begin
     ThreeHours = interval ''3 hours'';  -- throws a syntax error
     ThreeHours = ''3 hours''::interval; -- also throws a syntax error
end;
' LANGUAGE plpgsql;

In any reasonably modern version of PG, there's a string constant syntax
called "dollar quoting", which was invented specifically to make this
less painful:

CREATE FUNCTION ... AS $$
declare
     ThreeHours interval;
begin
     ThreeHours = interval '3 hours';  -- throws a syntax error
     ThreeHours = '3 hours'::interval; -- also throws a syntax error
end;
$$ LANGUAGE plpgsql;

If you need to use '$$' inside the function body, you could instead
use $func$ or something like that as the outer quoting boundaries.

(BTW, I would think that PgAdmin could handle these quoting details
for you, but I'm really not very familar with it.  Are you editing
the function in a window that's specifically for function editing?
If you're just typing the CREATE FUNCTION command as-is in a command
window, then you'll have to deal with the nested-quoting issues for
yourself.)

            regards, tom lane

Just to close the loop on my initial request, in the end we decided to go
with the approach of renaming the schema under the new name, dump it, rename
the schema back to its original name and do a restore of the dump, which will
recreate the schema under the new name.

Thanks to all for your suggestions, I will definitely keep the proposed
solution below in my notes!

---------------------------------
Daniel Gour
Adacel inc.

-----Original Message-----
From: Obe, Regina [mailto:robe.dnd@cityofboston.gov]
Sent: Wednesday, July 30, 2008 9:25 AM
To: Daniel Gour
Cc: pgsql-novice@postgresql.org
Subject: RE: [NOVICE] How to copy a schema under another name in same
database

Daniel,

I had a typo in the below that I just noticed.  Should be I think - but
I'm sure I screwed up in other ways, but hopefully you get the idea.


FOR tbltocopy IN(SELECT table_name
                FROM information_schema.tables
                WHERE table_type = 'BASE TABLE' AND
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE TABLE ' || param_dest_schema || '.' || tbltocopy
|| '( LIKE ' || param_source_schema || '.' || tbltocopy || ' INCLUDING
DEFAULT CONSTRAINTS INDEXES );
INSERT INTO ' || param_dest_schema || '.' || tbltocopy || ' SELECT *
FROM ' param_source_schema || '.' || tbltocopy || ';');

If you need to copy views as well, that's a bit trickier since I assume
you would want your views to reference the specific schema objects
within the destination schema not the source schema.

For that take a look at information_schema.views  -- it has a field
called view_definition.

You could use that to build the view and then macro replace the
references to the schema with the new schema I guess.

Something like
DECLARE vwdef information_schema.views  --this part is iffy not sure if
a type is created for information_schema stuff

FOR vwdef IN(SELECT *
                FROM information_schema.views
                WHERE
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE VIEW ' || param_dest_schema || '.' ||
vwdef.table_name
|| '( AS ' || REPLACE(vwdef.view_definition, param_source_schema || '.',
param_dest_schema || '.')
|| ';');

Hope that helps,
Regina

-----Original Message-----
From: Daniel Gour [mailto:Daniel.Gour@adacel.com]
Sent: Wednesday, July 30, 2008 9:12 AM
To: Obe, Regina
Cc: pgsql-novice@postgresql.org
Subject: RE: [NOVICE] How to copy a schema under another name in same
database

Thanks for the information!  That looks promising, I will attempt to
implement it this week and let you know.

---------------------------------
Daniel Gour
Adacel Inc.

-----Original Message-----
From: Obe, Regina [mailto:robe.dnd@cityofboston.gov]
Sent: Wednesday, July 30, 2008 7:14 AM
To: Daniel Gour; pgsql-novice@postgresql.org
Subject: RE: [NOVICE] How to copy a schema under another name in same
database

Never had a need for this.  One thought that comes to mind write a
plpgsql function that takes in name of new schema and old schema and
does something like below

--Create new tables in new schema

FOR tbltocopy IN(SELECT table_name
                FROM information_schema.tables
                WHERE table_type = 'BASE TABLE' AND
table_schema = param_source_schema ORDER BY table_name)

    EXECUTE('CREATE TABLE ' || param_dest_schema || '.' || tbltocopy
|| '( LIKE ' || param_source_schema || '.' || tbltocopy || ' INCLUDING
DEFAULT CONSTRAINTS INDEXES ');
INSERT INTO ' || param_dest_schema || '.' || tbltocopy || ' SELECT *
FROM ' param_source_schema || '.' || tbltocopy || ';');

NEXT;


Hope that helps,
Regina



-----Original Message-----
From: pgsql-novice-owner@postgresql.org on behalf of Daniel Gour
Sent: Tue 7/29/2008 9:20 AM
To: pgsql-novice@postgresql.org
Subject: [NOVICE] How to copy a schema under another name in same
database

Hello!  I have a PostgreSQL (8.3.3, WinXP + linux) database with
multiple
schemas.  I would like, on a regular basis, to be able to copy the
structure
and data of one schema under a new schema, using of course a different
name.
What would be the easiest way?



-          I have seen the TODO entry "Add CREATE SCHEMA ... LIKE that
copies
a schema", so I guess an easy solution (a single pgsql command) is not
yet
available...



-          I guess the alternative is to use pg_dump to dump a single
schema
and use pg_restore, but how can I restore the dumped information under
another schema?  I would like to avoid dumping it as an sql script and
having
it to modify it manually, because this will be a regular operation that
I
would like to automate in my application.



Thanks in advance for any insight you can provide!

---------------------------------
Daniel Gour
Adacel Inc.






-----------------------------------------
The substance of this message, including any attachments, may be
confidential, legally privileged and/or exempt from disclosure
pursuant to Massachusetts law. It is intended
solely for the addressee. If you received this in error, please
contact the sender and delete the material from any computer.