Delete/Create in the same transaction

Chandrashekhar Mullaparthi <>
Mon Apr 16 11:42:32 CEST 2001


6> mnesia:create_table(bag, [{attributes, [a,b]}, {type, bag}, {disc_copies,
[node()]}]).
{atomic,ok} 
.
.         
18> mnesia:transaction(fun() -> mnesia:write({bag, 1, 2}) end).
{atomic,ok}
19>
19>
19> mnesia:transaction(fun() -> mnesia:write({bag, 1, 3}) end).
{atomic,ok}
20>
20> [mnesia:dirty_read({bag, X}) || X <- mnesia:dirty_all_keys(bag)].
[[{bag,1,2},{bag,1,3}]]
21>
21> mnesia:transaction(fun() -> mnesia:delete_object({bag, 1, 2}),
mnesia:write({bag, 1, 2}) end).
{atomic,ok}
22>
22> [mnesia:dirty_read({bag, X}) || X <- mnesia:dirty_all_keys(bag)].
[[{bag,1,3}]]

In step 21, Why is it that if I delete an object in a transaction and write
it back again in the same, the object doesn't exist in the database??
Intuitively it seems to be a bug....

cheers,
Chandru



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