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Описание

string pg_field_name ( resource result, int field_number )

pg_field_name() returns the name of the field occupying the given field_number in the given PostgreSQL result resource. Field numbering starts from 0.

Замечание: This function used to be called pg_fieldname().

Список параметров

result: PostgreSQL query result resource, returned by pg_query(), pg_query_params() or pg_execute() (among others).
field_number: Field number, starting from 0.

Примеры

Пример 1. Getting information about fields

<?php $dbconn = pg_connect("dbname=publisher") or die("Could not connect"); $res = pg_query($dbconn, "select * from authors where author = 'Orwell'"); $i = pg_num_fields($res); for ($j = 0; $j < $i; $j++) { echo "column $j\n"; $fieldname = pg_field_name($res, $j); echo "fieldname: $fieldname\n"; echo "printed length: " . pg_field_prtlen($res, $fieldname) . " characters\n"; echo "storage length: " . pg_field_size($res, $j) . " bytes\n"; echo "field type: " . pg_field_type($res, $j) . " \n\n"; } ?>
Результат выполнения данного примера:
column 0 fieldname: author printed length: 6 characters storage length: -1 bytes field type: varchar column 1 fieldname: year printed length: 4 characters storage length: 2 bytes field type: int2 column 2 fieldname: title printed length: 24 characters storage length: -1 bytes field type: varchar

add a note User Contributed Notes
pg_field_name

12-Aug-2004 10:01


In fact you can extract the size of the varchar field, by simply sending the following query:

"select a.atttypmod,a.attrelid from pg_attribute as a, pg_class as c where c.relname='$table' AND a.attrelid=c.oid AND a.attname='$field'"



here is a simple function that does that:



function get_field_size($table, $field, $link) {

                

        $result = pg_query($link, "select a.atttypmod,a.attrelid from pg_attribute as a, pg_class as c where c.relname='$table' AND a.attrelid=c.oid AND a.attname='$field'");                 

        

        $data = pg_fetch_object($result);

        

        return ($data->atttypmod - 4);        

    

}



returned value is a size of a given field (also varchar)

ccasal at compuserve dot com
12-Jan-2001 11:51


The pg_fieldname function only returns the unqualified name from the select statement. example:



select c.name, con.name from customer c, contacts con where con.customer_id = c.id;



pg_fieldname will return "name" for both fields instead of c.name and con.name.



This is a PostgreSQL limitation, not a PHP limitation.



if you need different field names you should use :



select c.name as customer_name, con.name as contact_name from customer c, contacts con where con.customer_id = c.id;



then pg_fieldname will return "customer_name" and "contact_name"

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pg_field_name

Описание

Список параметров

Возвращаемые значения

Примеры

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