PHP 5.4.36 Released

pg_meta_data

(PHP 4 >= 4.3.0, PHP 5)

pg_meta_data Retorna os metadados da tabela.

Descrição

array pg_meta_data ( resource $connection , string $table_name )

pg_metadata() retorna a definição da tabela com o nome igual ao valor de table_name como um array. Se houver algum erro, retorna FALSE.

Exemplo #1 Obtendo os dados da tabela

<?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>';
    }
?>

O exemplo acima irá mostar a seguinte saída:

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)
  }
}

Aviso

Esta função é EXPERIMENTAL. O comportamento desta função, seu nome, incluindo toda documentação pode ser modificado sem aviso em futuras versões do PHP. Esta função deve ser usada por sua própria conta e risco.

Veja também pg_convert()

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User Contributed Notes 4 notes

up
1
yarnofmoo at gmail dot com
7 years ago
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';
up
0
jsnell at e-normous dot com
7 years ago
The built in function does not provide any support for selecting a schema.  If you need schema support and do not want to alter your SEARCH_PATH, the following function can provide it:

function meta_data($table, $schema = 'public')
    {
$result = pg_query_params("SELECT a.attname, a.attnum, t.typname, a.attlen, a.attnotNULL, a.atthasdef, a.attndims
FROM pg_class as c, pg_attribute a, pg_type t, pg_namespace n
WHERE a.attnum > 0
AND a.attrelid = c.oid
AND c.relname = $1
AND a.atttypid = t.oid
AND n.oid = c.relnamespace
AND n.nspname = $2
ORDER BY a.attnum", array($table, $schema));
$fields = array();
while($row = pg_fetch_array()) {
$fields['attname'] = $row;
}
        return $fields;
    }
up
0
dmiller at NOSPAM dot judcom dot nsw dot gov dot au
11 years ago
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
up
-1
rburghol at vt dot edu
9 years ago
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 ...
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