Erlang Mailing Lists
Author Message

<  Erlang patches mailing list  ~  mnesia_schema patch
etxuwig at etxb.ericsson.
Posted: Mon Mar 10, 2003 3:19 pm Reply with quote
Guest
The attached patch to mnesia_schema (mnesia-4.1.3) exports
the do_delete_table/1 function. This is symmetrical to the
already exported do_create_table/1.

The use of both is to be able to do something like the
following:

add_context(Context) ->
mnesia_schema:schema_transaction(
fun() ->
case mnesia:read(context, Context, read) of
[] ->
mnesia:write(#context{id=Context}),
lists:foreach(
fun({TabName, Opts}) ->
Cs = mnesia_schema:list2cs(
add_name(TabName, Opts)),
mnesia_schema:do_create_table(Cs)
end, sub_tables(Context));
_ ->
mnesia:abort({exists, Context})
end).

remove_context(Context) ->
mnesia_schema:schema_transaction(
fun() ->
case mnesia:read(context,Context, write) of
[_] ->
mnesia:delete(context,Context,write),
lists:foreach(
fun({TabName,_}) ->
mnesia_schema:do_delete_table(TabName)
end, sub_tables(Context));
[] ->
mnesia:abort({not_found, Context})
end).

...without totally messing up your database upon partial
failure.

/Uffe
--
Ulf Wiger, Senior Specialist,
/ / / Architecture & Design of Carrier-Class Software
/ / / Strategic Product & System Management
/ / / Ericsson AB, Connectivity and Control Nodes


Post generated using Mail2Forum (http://m2f.sourceforge.net)
Back to top
dgud at erix.ericsson.se
Posted: Mon Mar 10, 2003 3:29 pm Reply with quote
Guest
Ok, will be added in the next patch/release.
/Dan

Ulf Wiger writes:
>
> The attached patch to mnesia_schema (mnesia-4.1.3) exports
> the do_delete_table/1 function. This is symmetrical to the
> already exported do_create_table/1.
>
> The use of both is to be able to do something like the
> following:
>
> 102a103
> > do_delete_table/1,



Post generated using Mail2Forum (http://m2f.sourceforge.net)
Back to top

Display posts from previous:  

All times are GMT
View next topic
View previous topic
Page 1 of 1
Erlang Forum - Trap Exit Forum Index  ~  Erlang patches mailing list
This forum is locked: you cannot post, reply to, or edit topics.

Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum
Hosted by Erlang Solutions    |    Powered by phpBB and NoseBleed v1.14