pg_field_name

(PHP 4 >= 4.2.0, PHP 5)

pg_field_name -- Returns the name of a field

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.

Возвращаемые значения

The field name, or FALSE on error.

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

Смотрите также

pg_field_num()



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"

<pg_field_is_nullpg_field_num>
 Last updated: Tue, 15 Nov 2005