On 01/12/2013 04:58 PM, Robert James wrote:
Typically, my web application does some initial validation, then, if
it passes, does the actual query. For both performance and
simplicity, I'd like to combine these all into one trip to Postgres.
Ideally, I'd like to do this in SQL. If that's not possible, I could
use PL/pgsql, though I'm not adept at it.
Example #1:
qry = "SELECT 1 FROM users WHERE username = ? AND PASSWORD = ?"
if qry.count > 0
qry = "SELECT ..."
Example #2:
qry = "SELECT 1 FROM users WHERE username = ? AND PASSWORD = ?"
if qry.count > 0
qry = "SELECT product WHERE ..."
if qry.count > 0
qry = "UPDATE product SET..."
How can I combine these into one Postgres call? I'd like it to look
something like:
GET_PRODUCTS(username, password) -- Returns products, or -1 if
username bad, -2 if password is bad
UPDATE_PRODUCTS(username, password, productid, newval) -- Updates
product, Returns 0 if good, -1 if username bad, -2 if password bad, -3
if productid bad
So where are you running the above functions?
I would say you are going to end up using some procedural language to do
what you want. PL/pgsql is not that difficult to learn. If you end up
creating the functions on the server using plpgsql then you get your
simple query:
select get_products(username, password);
--
Adrian Klaver
adrian.klaver@xxxxxxxxx
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