pg_field_size

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

pg_field_size Returns the internal storage size of the named field

Опис

pg_field_size(PgSql\Result $result, int $field): int

pg_field_size() returns the internal storage size (in bytes) of the field number in the given PostgreSQL result.

Зауваження:

This function used to be called pg_fieldsize().

Параметри

result

Примірник PgSql\Result, якого повертає одна з функцій pg_query(), pg_query_params() або pg_execute() (серед інших).

field

Field number, starting from 0.

Значення, що повертаються

The internal field storage size (in bytes). -1 indicates a variable length field.

Журнал змін

Версія Опис
8.1.0 Тепер параметр result має бути примірником PgSql\Result. Раніше очікувався resource.

Приклади

Приклад #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";
}
?>

Поданий вище приклад виведе:

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

Прогляньте також

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User Contributed Notes 3 notes

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0
ij at NOSPAM dot irj dot co dot za
20 years ago
To view the file structure of a table using a sql queryselect pg_class.relname, pg_attribute.attname, pg_type.typname, pg_type.typlen from pg_class, pg_attribute, pg_type  where pg_class.relname = 'YOURTABLENAME' and pg_class.oid = pg_attribute.attrelid and pg_type.oid = pg_attribute.atttypid having attnum > 0
up
0
php at tribun dot de
20 years ago
function get_create_syntax( $table ){  $qry  =  "            SELECT    *            FROM      $table            LIMIT     1          ";  $res = pg_query( $qry );  $row = pg_fetch_assoc( $res );  $create = "CREATE TABLE $table \n(\n";  $item = array();  for( $i = 0; $i < count( $row ); $i++ )  {    $name = pg_field_name( $res, $i );    $type = pg_field_type( $res, $i );    $size = pg_field_size( $res, $i );    $item[$i] = '"'.$name.'" '.$type;    $qry  =  "              SELECT    a.atttypmod    AS size,                        a.attnotnull  AS notnull              FROM      pg_attribute  AS a,                        pg_class      AS c              WHERE     c.relname   = '$table'              AND       a.attrelid  =  c.oid              AND       a.attname    =  '$name'             ";    $res2  = pg_query( $qry );    $out  = pg_fetch_object( $res2 );    if( $out -> size != -1 )    {      $item[$i] .= '('.( $out -> size - 4 ).')';    }    if( $out -> notnull == 't' )    $item[$i] .= ' NOT';    $item[$i] .= ' NULL';  }  $create .= implode( ",\n", $item ) ."\n);";  return $create;}
up
-3
alex at linuxNOSPAM dot org dot pe
23 years ago
How i can extract the struct of a Postgresql Table?I want to do a dynamic php code, that see the pg table, and print name, type and size of fields
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