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Last updated: Sat, 27 Jan 2007

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# pg_meta_data

(PHP 4 >= 4.3.0, PHP 5)

pg_meta_data -- Get meta data for table

## 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.

## Возвращаемые значения

An array of the table definition, or `FALSE` on error.

## 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)
    }
    }

## Смотрите также

pg_convert()

add a note User Contributed Notes
pg_meta_data
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_num_fields pg_lo_write

Last updated: Sat, 27 Jan 2007
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