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Описание

array pg_meta_data ( resource connection, string table_name )

pg_meta_data() returns table definition for table_name as an array.

Внимание

Эта функция является ЭКСПЕРИМЕНТАЛЬНОЙ. Поведение этой функции, ее имя и относящаяся к ней документация могут измениться в последующих версиях PHP без уведомления. Используйте эту функцию на свой страх и риск.

Список параметров

connection: PostgreSQL database connection resource.
table_name: The name of the table.

Примеры

Пример 1. Getting table metadata

<?php $dbconn = pg_connect("dbname=publisher") or die("Could not connect"); $meta = pg_meta_data($dbconn, 'authors'); if (is_array($meta)) { echo '<pre>'; var_dump($meta); echo '</pre>'; } ?>
Результат выполнения данного примера:
array(3) { ["author"]=> array(5) { ["num"]=> int(1) ["type"]=> string(7) "varchar" ["len"]=> int(-1) ["not null"]=> bool(false) ["has default"]=> bool(false) } ["year"]=> array(5) { ["num"]=> int(2) ["type"]=> string(4) "int2" ["len"]=> int(2) ["not null"]=> bool(false) ["has default"]=> bool(false) } ["title"]=> array(5) { ["num"]=> int(3) ["type"]=> string(7) "varchar" ["len"]=> int(-1) ["not null"]=> bool(false) ["has default"]=> bool(false) } }

add a note User Contributed Notes
pg_meta_data

yarnofmoo at gmail dot com
27-Jun-2007 08:32


You can get some possibly more useful information with the query:



SELECT table_name, column_name, data_type, character_maximum_length FROM information_schema.columns WHERE table_name='tablename';

rburghol at vt dot edu
24-Jun-2005 06:37


When querying on meta data from a temp table, the meta data seems to persist even if a fresh connection is established, where the temp table no longer exists.



 For example, if you create a connection and a temp table like so:

$dbconn1 = pg_connect('blah blah', , PGSQL_CONNECT_FORCE_NEW);

pg_exec($dbconn1,'create temp table foo as select 'foo' as namecol, 'bar' as valcol');



Then create a new connection



$dbconn2 = pg_connect('blah blah', , PGSQL_CONNECT_FORCE_NEW);



And query the meta data for table 'foo' in this new connection, it will report the facts about this table:

pg_meta_data($dbconn2,'foo');



"'Array ( [foo] => Array ( [num] => 1 [type] => varchar... "



However, trying to remove this table:

pg_exec($dbconn,'drop table foo');



Throws an error:

pg_exec(): Query failed: ERROR: table "foo" does not exist in ...

dmiller at NOSPAM dot judcom dot nsw dot gov dot au
18-Jun-2003 01:31


This function seems to be case-sensitive on tablename (php-4.3.1)



The Array returned is of the following structure

['field name'] => Array

   (

     ['num'] => Field number starting at 1

     ['type'] => data type, eg varchar, int4

     ['len'] => internal storage size of field. -1 for varying

     ['not null'] => boolean

     ['has default'] => boolean

   )

     ......



for Varied size datatypes (varchar, text, etc) 

you can get the max data length from the system table pg_attribute.atttypmod -4

eg. 

select attnum, attname , atttypmod -4 as field_len 

from pg_attribute, pg_class 

where relname='$tablename' 

and attrelid=relfilenode 

and attnum>=1

add a note

pg_meta_data

Описание

Список параметров

Возвращаемые значения

Примеры

Смотрите также