Thread: FW: Working with XML.

FW: Working with XML.

From

Theo Galanakis

Date:

21 February 2005, 08:32:26

Hi,

I have copied all the files manually from http://developer.postgresql.org/docs/pgsql/contrib/ for the xml2 contribution. However I have the following issue when I attempt to compile with gmake:

gcc -I/usr/include/libxml2 -fpic -I. -I../../src/include -D_GNU_SOURCE -c -o xpath.o xpath.c
xpath.c: In function `xpath_table':
xpath.c:689: `work_mem' undeclared (first use in this function)
xpath.c:689: (Each undeclared identifier is reported only once
xpath.c:689: for each function it appears in.)
gmake: *** [xpath.o] Error 1

I have installed :

libxml2-devel-2.5.10-1.rpm

What am I doing wrong, or can someone point me to the direction of a binary for XML2 on RedHat ES3, Postgres 7.4.5.

Cheers,

Theo

-----Original Message-----
From: Theo Galanakis
Sent: Monday, 21 February 2005 11:52 AM
To:
Subject: FW: [SQL] Working with XML.

Hi George,

Thanks for your help once again.

However I cant seem to find XML2, the contrib package for RedHat ES3 I downloaded only has xml. Where can I find the compiled or source code. The only link I have is http://developer.postgresql.org/docs/pgsql/contrib/ , it there ftp access or cvs access to contrib?

Theo

-----Original Message-----
From: George Weaver [mailto:gweaver@shaw.ca]
Sent: Wednesday, 16 February 2005 12:37 AM
To: Theo Galanakis
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Working with XML.

Hi Theo,

I'm not sure if it can be done with the xml contrib module. You may want to install and work with the xml2 contrib module, which is more recent, has more extensive capabilities, and is easier to work with.

It will give you the result you want:

jan28-05=# select xpath_string(
jan28-05(# '<query columns="4" rows="100"><row><cola>284122</cola><colb>789648</colb><
colc>{ts ''2005-02-14 16:13:18''}</colc><cold>unbnda8m5946z55sgi1xco34h1q9tLonoys3nyk1
d5tgtLaw8h5wya0zdv7vigeiuk9xqLuacdy0dsisopb8g1o4o76090otmq65</cold></row><row><cola>24
3151</cola><colb>750292</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>2d4mat2Lp
tmdydtgqnc5vnuzxgqxiykqn1c4pr0oduk5gwz25b3Lq05dzqxetee9om45b69ytb48uvziL5xrvyu4k7ng4oo
uihx0</cold></row><row><cola>764929</cola><colb>641215</colb><colc>{ts ''2005-02-14 16
:13:18''}</colc><cold>1z5x6dLc9n1vtcLbmk7q6hdriqLa2ub4et41podr7izcro4nkkLsvp9p0s7obzr2
7txvknn92m0ps4riqqx7puqoLn2wpmm2z50r</cold></row></query>'
jan28-05(# ,'//query/@rows') as rows;

rows
------
100
(1 row)

Another example:

jan28-05=# select xpath_string(
jan28-05(# '<query columns="4" rows="100"><row><cola>284122</cola><colb>789648</colb><
colc>{ts ''2005-02-14 16:13:18''}</colc><cold>unbnda8m5946z55sgi1xco34h1q9tLonoys3nyk1
d5tgtLaw8h5wya0zdv7vigeiuk9xqLuacdy0dsisopb8g1o4o76090otmq65</cold></row><row><cola>24
3151</cola><colb>750292</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>2d4mat2Lp
tmdydtgqnc5vnuzxgqxiykqn1c4pr0oduk5gwz25b3Lq05dzqxetee9om45b69ytb48uvziL5xrvyu4k7ng4oo
uihx0</cold></row><row><cola>764929</cola><colb>641215</colb><colc>{ts ''2005-02-14 16
:13:18''}</colc><cold>1z5x6dLc9n1vtcLbmk7q6hdriqLa2ub4et41podr7izcro4nkkLsvp9p0s7obzr2
7txvknn92m0ps4riqqx7puqoLn2wpmm2z50r</cold></row></query>'
jan28-05(# ,'//row[cola=284122]/colb') as colb;

colb
--------
789648
(1 row)

HTH,

George
----- Original Message -----
From: Theo Galanakis
To: 'George Weaver'
Cc: 'pgsql-sql@postgresql.org'
Sent: Monday, February 14, 2005 9:46 PM
Subject: RE: [SQL] Working with XML.

Thanks George.

    How do you get an attributes value the following returns the attribute tag. i.e. rows="100", all i want is the 100.
   select
pgxml_xpath(
'<query columns="4" rows="100"><row><cola>284122</cola><colb>789648</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>unbnda8m5946z55sgi1xco34h1q9tLonoys3nyk1d5tgtLaw8h5wya0zdv7vigeiuk9xqLuacdy0dsisopb8g1o4o76090otmq65</cold></row><row><cola>243151</cola><colb>750292</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>2d4mat2Lptmdydtgqnc5vnuzxgqxiykqn1c4pr0oduk5gwz25b3Lq05dzqxetee9om45b69ytb48uvziL5xrvyu4k7ng4oouihx0</cold></row><row><cola>764929</cola><colb>641215</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>1z5x6dLc9n1vtcLbmk7q6hdriqLa2ub4et41podr7izcro4nkkLsvp9p0s7obzr27txvknn92m0ps4riqqx7puqoLn2wpmm2z50r</cold></row></query>'
,'//query/@rows','','')
Theo

-----Original Message-----
From: George Weaver [mailto:gweaver@shaw.ca]
Sent: Tuesday, 15 February 2005 12:39 AM
To: Theo Galanakis; pgsql-sql@postgresql.org
Subject: Re: [SQL] Working with XML.

Hi Theo,

I am not aware of any means of passing xml to stored procedures, apart from writing your own function to parse the xml.

In regard to your second question - how to access the second record - try using a more explicit xpath query incorporating a "where" component. For example, if you wanted to access the second row based upon the value of cola, you could use '//query/row[@cola='525887']/text()'. Or you could specify the position of the record if you know its position: '//query/row[2]/text()'.

Microsoft has a very good reference on xpath expressions: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/html/xmrefxpathsyntax.asp.

Regards,
George
----- Original Message -----
From: Theo Galanakis
To: pgsql-sql@postgresql.org
Sent: Sunday, February 13, 2005 11:48 PM
Subject: [SQL] Working with XML.

Hi Folks,
Is there a way to pass in an xml string into a stored proc and thenplace this into a temp table?
I use to be able to do this in sql server, it was quite handy as I could call one stored proc to update multiple records, here is a sample in sql server:
select CoverTypeID, ItemSQ, SituationID, ItemDescription, CoverAmount
From OpenXML ( @XmlHandle, '/cover/covertype/item',1 )
            With ( CoverTypeID int '../@id',
                      ItemSQ int '@id',
                      SituationID int '@situationID',
                      ItemDescription varchar(100) '@description',
                      CoverAmount money '@amount' )
I have managed to get get pgxml_xpath working, however Im not sure how to access specific rows in an xml document. E.g below there are two records, how do I access the second record, the following returns both ,'//query/row/cola values being (284122,525887):
select
pgxml_xpath(
'<query columns="4" rows="100"><row><cola>284122</cola><colb>789648</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>unbnda8m5946z55sgi1xco34h1q9tLonoys3nyk1d5tgtLaw8h5wya0zdv7vigeiuk9xqLuacdy0dsisopb8g1o4o76090otmq65</cold></row<row><cola>525887</cola><colb>493253</colb><colc>{ts ''2005-02-14 16:13:18''}</colc><cold>6uydk442uz247ga45kpys7htkxznkn8La31qhn942wu2cu2pdr25mv2nup2zh3vcbh3c4vdauak3p3w093cvtkeyga692b455cr3</cold></row></query>'
,'//query/row/cola/text()','','')
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Re: Working with XML.

From

George Weaver

Date:

21 February 2005, 17:55:59

Hi Theo,

There have been 2 major changes between the 7 and 8 versions that affect the coding in xml2. You need to edit the source code in order for it to compile properly on 7.

First, work_mem has to be changed to SortMem (line 666). I.e.

tupstore = tuplestore_begin_heap(true, false, work_mem);

should be changed to:

tupstore = tuplestore_begin_heap(true, SortMem);

Second, the error reporting framework has changed.

To fix this, you need to change all the ereport coding to use elog. I.e.

ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table must be called as a table function")));

should be changed to:

elog(ERROR,"xpath_table must be called as a table function");

I have attached an edited copy of xpath.c with these changes, if you would like to work with it.

Regards,

George

----- Original Message -----
From: Theo Galanakis
To: 'pgsql-sql@postgresql.org'
Sent: Sunday, February 20, 2005 11:28 PM
Subject: FW: [SQL] Working with XML.

Hi,
    I have copied all the files manually from http://developer.postgresql.org/docs/pgsql/contrib/ for the xml2 contribution. However I have the following issue when I attempt to compile with gmake:

gcc -I/usr/include/libxml2 -fpic -I. -I../../src/include -D_GNU_SOURCE   -c -o xpath.o xpath.c
xpath.c: In function `xpath_table':
xpath.c:689: `work_mem' undeclared (first use in this function)
xpath.c:689: (Each undeclared identifier is reported only once
xpath.c:689: for each function it appears in.)
gmake: *** [xpath.o] Error 1

I have installed :

    libxml2-devel-2.5.10-1.rpm

What am I doing wrong, or can someone point me to the direction of a binary for XML2 on RedHat ES3, Postgres 7.4.5.

Cheers,
    Theo

Attachment

xpath.c

Re: FW: Working with XML.

From

Mirko Zeibig

Date:

23 February 2005, 09:43:26

Theo Galanakis wrote:
> Hi, 
>     I have copied all the files manually from http
> <http://developer.postgresql.org/docs/pgsql/contrib/>
> ://developer.postgresql.org/docs/pgsql/contrib/ for the xml2 contribution.
> However I have the following issue when I attempt to compile with gmake:
>  
> gcc -I/usr/include/libxml2 -fpic -I. -I../../src/include -D_GNU_SOURCE   -c
> -o xpath.o xpath.c
> xpath.c: In function `xpath_table':
> xpath.c:689: `work_mem' undeclared (first use in this function)
> xpath.c:689: (Each undeclared identifier is reported only once
> xpath.c:689: for each function it appears in.)
> gmake: *** [xpath.o] Error 1
>  
> I have installed :
>  
>     libxml2-devel-2.5.10-1.rpm
>  
> What am I doing wrong, or can someone point me to the direction of a binary
> for XML2 on RedHat ES3, Postgres 7.4.5.

Hello Theo,

this has nothing to do with libxml2. `work_mem` is a variable declared 
in one of the PostgreSQL include files. The `-I../../src/include` 
directive in the compile statement above should point to the include-dir 
of your PostgreSQL installation.

Regards
Mirko