|
|
 |
LXXX. PostgreSQL f�ggv�nyek
Postgres, amit eredetileg a UC Berkeley Computer Science
Department fejlesztett ki, �tt�r� volt az objektum-rel�ci�s adatmodellek ter�let�n, �s most el�rhet�v� v�lik t�bb kereskedelmi adatb�zisban is.
T�mogatja az SQL92/SQL3 nyelv haszn�lat�t, tranzakci�k integrit�s�t �s a
t�pusok kiterjeszthet�s�g�t. A PostgreSQL egy public-domain,
ny�lt forr�s� lesz�rmazottja ennek az eredeti Berkeley k�dnak.
A PostgreSQL ingyenes. A leg�jabb verzi� a
c�men �rhet� el.
A 6.3 verzi� �ta (03/02/1998) a PostgreSQL unix socketeket haszn�l.
A lenti t�bl�zat mutatja az �j kapcsolatteremt�si lehet�s�geket.
Ez a socket a /tmp/.s.PGSQL.5432 n�ven �rhet� el.
Ezt az opci�t a postmaster parancs '-i'
kapcsol�j�val �rheted el, a jelent�se pedig:
"figyeld a TCP/IP socketeket is �gy, mint a unix socketeket".
T�bl�zat 1. Postmaster �s a PHP | Postmaster | PHP | �llapot |
|---|
| postmaster & | pg_connect("", "", "", "", "dbname"); | OK | | postmaster -i & | pg_connect("", "", "", "", "dbname"); | OK | | postmaster & | pg_connect("localhost", "", "", "", "dbname"); |
Unable to connect to PostgreSQL server: connectDB() failed:
Is the postmaster running and accepting TCP/IP (with -i)
connection at 'localhost' on port '5432'? in
/path/to/file.php3 on line 20.
vagyis:
Nem lehet kapcsol�dni a PostgreSQL szerverhez: a connectDB() h�v�s
meghi�sult. Fut a postmaster, �s fogadja a TCP/IP kapcsolatokat (-i)
a helyi g�pen az 5432-es porton? a
/el�r�si_�t/a/file.php3 a 20-as sorban
| | postmaster -i & | pg_connect("localhost", "", "", "", "dbname"); | OK |
A k�vetkez�k�pp is kezdhetsz kapcsolatot:
$conn = pg_Connect("host=localhost port=5432
dbname=chris");
Annak �rdek�ben, hogy haszn�lhassunk nagy objektum fel�letet (lo),
sz�ks�ges az eg�szet egy tranzakci�s blokkba foglalni. A tranzakci�s
blokk egy begin-nel kezd�dik, �s ha a tranzakci�
�rv�nyes, egy commit-tal vagy egy
end-del v�gz�dik. Ha a tranzakci� meghi�sul, akkor
rollback vagy abort paranccsal
kell v�gz�dnie.
P�lda 1. Nagy objektumok haszn�lata <?php
$database = pg_Connect ("", "", "", "", "jacarta");
pg_exec ($database, "begin");
$oid = pg_locreate ($database);
echo ("$oid\n");
$handle = pg_loopen ($database, $oid, "w");
echo ("$handle\n");
pg_lowrite ($handle, "gaga");
pg_loclose ($handle);
pg_exec ($database, "commit");
?> |
|
User Contributed Notes
PostgreSQL f�ggv�nyek |
  |
[email protected]
02-Mar-2000 07:36 |
|
If you want to see all the objects in a database, you can find that
information in the pg_class table.
SELECT * FROM
pg_class;
Now this is going to be kind of long and complex, to see
how psql command handles the \d and other things. use the syntax. psql -E
<Database>, ie psql -E mydatabase
What this will do is show
the SQL command used for everything. So when you type a \d or something,
it shows the SQL query used for the result.
|
|
|
18-May-2000 12:29 |
|
Ways of getting the value of a generated serial are discussed at
|
|
jdb30 at cornell.edu
06-Dec-2000 07:08 |
|
For further reading on PostgreSQL, see:
|
|
[email protected]
15-Apr-2001 08:11 |
|
If you want to extract data from select statements, you need to store the
result index, and then apply pg_result to that value. Basically, do
this
$resultIdx = pg_query ($database, "select * from
tablename");
$mySelect = pg_fetch_result($resultIdx, 0, 0); //
gets column 0 of tuple 0
echo("My select:
[".$mySelect."]");
I'm new to php and had to do
some fiddling around to work this out. It's reasonably elementary, but not
demonstrated by the examples on these pages. Hopefully it will come in
useful to someone else.
|
|
passion at monkey dot org
28-Jun-2001 01:53 |
|
I've tried to mimic the following mysql database connection functions for
postgres.
These
are assuming that you're passing in $link as the result from
pg_connect:
function pg_list_dbs($link)
{
$sql =
'SELECT datname FROM pg_database';
return (pg_query($link,
$sql));
}
function pg_list_tables($link)
{
$sql = "SELECT relname FROM pg_class WHERE relname !~
'^pg_'";
return (pg_query($link, $sql));
}
|
|
[email protected]
09-Jul-2001 11:36 |
|
The best way to find the separated list of tables, sequences, keys etc
is:
SELECT relname FROM pg_class WHERE relkind='<value>'
AND relname !~ '^pg_';
<value> takes:
i for keys,
r
for relations,
S for sequences
Note that all tables names
that begins with 'pg_' are PostgreSQL internal tables (this explain why I
use AND relname !~ '^pg_' condition).
|
|
[email protected]
31-Jul-2001 09:45 |
|
in debian, you need to include
dl('pgsql.so')
in all
your scripts of php4. I think its different for PHP3 -
dl('libpg.so')
[Editor's Note]
Debian users should
be able to use "extension" directive to load pgsql.so. This
method is prefered method if you use pgsql module always.
|
|
[email protected]
15-Sep-2001 09:11 |
|
I tried compiling PHP from source with PostgreSQL support (./configure
--with-pgsql=/usr/local/pgsql) and ran into a bunch of problems when
trying to 'make'. The problem was that some of the PostgreSQL headers were
not installed by default when I installed PostgreSQL from source. When
installing PostgreSQL make sure you 'make install-all-headers' after you
'make install'.
|
|
[email protected]
04-Feb-2002 02:46 |
|
Nice to know fact that I didn't find documented here.
PHP will
return values of PostgreSQL boolean datatype as single character strings
"t" and "f", not PHP true and
false.
[Editor's Note]
't' or 'f' is valid boolean expression
for PostgreSQL.
All values from PostgreSQL are strings, since
PostgreSQL integer, float may be much larger than PHP's native int, double
can handle. PostgreSQL array is not supported.
|
|
[email protected]
22-Aug-2002 03:49 |
|
My talk on PHP and PostgreSQL which I presented at O'Reilly OSCON 2002 is
now online.
|
|
|
|
| |
posix_uname