PHP: pg_meta_data

説明

array pg_meta_data ( resource connection, string table_name )

pg_meta_data() は、table_name のテーブル定義を配列として返します。

警告

この関数は、 実験的 なものです。この関数の動作・名前・その他ドキュメントに書かれている事項は、予告なく、将来的な PHP のリリースにおいて変更される可能性があります。この関数は自己責任で使用してください。

パラメータ

connection: PostgreSQL データベースの接続リソース。
table_name: テーブルの名前。

例

例 1. テーブルのメタデータを得る

<?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>'; } ?>
上の例の出力は以下となります。
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

rburghol at vt dot edu
24-Jun-2005 10:37


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 05:31


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

説明

パラメータ

返り値

例

参考


	downloads \| documentation \| faq \| getting help \| mailing lists \| reporting bugs \| php.net sites \| links \| my php.net

search for in the