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Re: getting all name-value pairs from a dynamic column
> Isn't this request something like this
> http://dev.mysql.com/doc/refman/5.1/en/xml-functions.html - only not only
> XML but also JSON should be supported?
yes! its a more useful format, as Mark points out below, I have code for
it. I'll test it on a more recent version of mariadb in the next couple
days, and unearth my old design, I'll respond with code in the next few
days I am physically separate currently from my archived code. I would
love to see someone make use of it.
> I remember when this XML functionality was introduced in early MySQL 5.1
> there was quite a lot of *buzz* about it. I never heard anything about it
> since. I have not even seen a bug report! It seems that nobody knows it
> nobody uses it.
> I agree that JSON is an important format. But there are lots such. A
> little polemically I could say that as since some people store .mp3/.mp4
> snippets in a BLOB why not add a media streaming functionality to the
> server ... and playback functionalities to the standard client :-)
> I think such stuff belongs in a 'stored functions library' and are not a
> core server feature. But I realize that as long as stored functions
> programming only supports SQL (and not Perl like in Postgsql and not C# as
> in recent SQL Server) it is not really much feasible. Currently it
> coding in the application/client environment (such as a PHP class for
> (you may find this an off-topic comment from a non-coder (and you are
> right) - but I wanted to put a little perspective on this. IMHO this
> reqeust arises bcos of poor 'stored programs' programming options in
> -- Peter
> -- Webyog
> On Wed, Apr 11, 2012 at 19:40, MARK CALLAGHAN <mdcallag@xxxxxxxxx> wrote:
>> I think I want a function that converts the blob into a JSON formatted
>> set of key-value pairs.
>> On Wed, Dec 7, 2011 at 9:19 PM, MARK CALLAGHAN <mdcallag@xxxxxxxxx>
>> > On Fri, Dec 2, 2011 at 5:23 AM, Michael Widenius <monty@xxxxxxxxxxxx>
>> >> MARK> How do you fetch all name-value pairs from a dynamic column in
>> >> MARK> format that can be consumed by a client?
>> >> Do you mean from SQL or in the client library?
>> > In the client
>> >> MARK> The client can select the
>> >> MARK> column as is but then must know how mariadb encoded it.
>> >> Sorry, don't understand the question.
>> >> When asking for a value for a column in the client , you get back a
>> >> structure that tells how the data is encoded. See the 'struct
>> >> st_dynamic_column_value'
>> >> MARK> The function
>> >> MARK> column_list returns the column names.
>> > Dynamic columns are dynamic. The client doesn't know which key names
>> > are used for each row selected. With the current code there is no way
>> > for the client to get all key:value pairs set in a dynamic column for
>> > some number of rows. They can select the column but probably won't
>> > know how to decode the name:value pairs stored in it.
>> > Apparently Jakob has code for this. So I don't have much more to add
>> > for this thread.
>> > --
>> > Mark Callaghan
>> > mdcallag@xxxxxxxxx
>> Mark Callaghan
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