i am trying to run a query but its not working may be due to constraint
conflicts
i have table A, B and C
B and C have a foreign key linked with A's primary key
so i want to delete an entry from A
for that i hav to delete child records first
can u design a query which wont conflict the
To be precise, if you used defaults, you can't delete any row in table A
that has rows referencing to it in tables B and C.
On Tue, Nov 30, 2010 at 6:59 AM, manidegr8 engineer.us...@ymail.com wrote:
i am trying to run a query but its not working may be due to constraint
conflicts
i have
Here is my take on how to regard parent tables in one-to-many FK relationships.
If lets say we have a situation when we model e.g. mail messages and its
attachments, then we might want to use ON DELETE CASCADE since
there is absolutely no reason for an attachment to exist when the main message
Try it:
select zonas.zona_id, usr_folio from zonas left join usuarios on (*per_id =
2 and *zonas.zona_id = usuarios.zona_id) order by zonas.zona_id;
Or:
select zonas.zona_id, usr_folio from zonas left join usuarios on
zonas.zona_id = usuarios.zona_id where per_id = 2 *or usuarios.zona_id is
* Stefan Becker:
Is there a way to get the ID row OR create a new one in
ONE single statement?
You could create a stored procedure. But if you have concurrent
inserts, locking is a bit tricky.
--
Florian Weimerfwei...@bfk.de
BFK edv-consulting GmbH http://www.bfk.de/
yes i know about on delete cascade
it automatically delete the child when master is deleted
but the database i m working on is not built in this fashion
tables r built on default rules
so constraints r there
i m jus asking to build a procedure or function
that taking from the user and deletes
Were we to create a table which included a text field for a small block
of xml (100-1000 chars worth), would an index on that field be useful
against exact match queries?
We're wondering if a criterion such as where 'a string expected to be
of size range 100 to 500' =
Why don't you use some type of hash like md5 for indexing ?
2010/11/30 Rob Sargent robjsarg...@gmail.com:
Were we to create a table which included a text field for a small block
of xml (100-1000 chars worth), would an index on that field be useful
against exact match queries?
We're wondering
If the performance against an index doesn't cut it, we would be forced
to choose just such an implementation, but if pg can do it straight up
that would be less work for us. A good thing, to be sure.
On 11/30/2010 10:50 AM, jose wrote:
Why don't you use some type of hash like md5 for indexing ?
You can use a hash index for this. It's drawback is that it is not
yet WAL enabled and if your DB crashes you will need to rebuild the
index to fix the corruption. It works well(only) with equality
searches. If it is a scenario where you must have WAL, use a
function index based on the hash of the
Hi,
While hashing is certainly a good idea, you really should consider some
issues well before you get to that point. Trust me, this could save you some
headaches. First, though you're probably already aware, two XML documents
can be the same document, but with very different literal
On tor, 2010-11-25 at 14:42 +0900, Chang Chao wrote:
How strings are sorted when LC_COLLATE = ja_JP.UTF-8.
I tried to read the documention on that,but there are just a few
words,
like LC_COLLATE determines string sort order,
Is there a specific reference about this?
So I can implement an
No problem, sir, hopefully I could help. I failed to mention that I've
discovered some bugs in the PostgreSQL 8.4 XML implementation that forced me
to take pause and ultimately forego XML with Postgres. I haven't looked at 9
yet, but considering the current lack of interest and/or disdain so many
I have a fact table with a number of foreign keys to dimension data and some
measure columns. Let's assume I've got dimension columns a,b,c,d,e, and f
and measure columns x, and y.
I need to be able to find the value of f, x, and y for the row with min(x/y)
when e in (1,2) and max(x/y) when e
Hi,
How do I load a Census shp file into an exist database? I believe I have
postGIS install and now I want to load the US counties shp file.
the following does not appear to work
shp2pgsql -s 4269 -I -W latin1 tl_2008_us_county.shp 2008_us_county | psql
Plus I don't know what it does!
I want to delete certain rows from table USER_TBL.
Two tables are involved. USER_TBL and OWNER_TBL.
The entries that match BLAND type in OWNER table and who also have a
matching entry in USER table NAME but only for USER_TBL entries with
places equal to HOME.
DELETE FROM SP.TST_USER_TBL
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