pg_field_table

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

pg_field_table — Returns the name or oid of the tables field

Опис

pg_field_table(PgSql\Result $result, int $field, bool $oid_only = false): string|int|false

pg_field_table() returns the name of the table that field belongs to, or the table's oid if oid_only is true.

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.
oid_only: By default the tables name that field belongs to is returned but if oid_only is set to true, then the oid will instead be returned.

Значення, що повертаються

On success either the fields table name or oid, або false в разі помилки.

Журнал змін

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

Приклади

Приклад #1 Getting table information about a field

<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");

$res = pg_query($dbconn, "SELECT bar FROM foo");

echo pg_field_table($res, 0);
echo pg_field_table($res, 0, true);

$res = pg_query($dbconn, "SELECT version()");
var_dump(pg_field_table($res, 0));
?>

Поданий вище приклад виведе щось схоже на:

foo
14379580

bool(false)

Примітки

Зауваження:
Returning the oid is much faster than returning the table name because fetching the table name requires a query to the database system table.

Прогляньте також

pg_field_name() - Returns the name of a field
pg_field_type() - Returns the type name for the corresponding field number

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User Contributed Notes 2 notes

down

strata_ranger at hotmail dot com ¶

15 years ago

pg_field_table is primarily useful for queries that involve joins between multiple tables, e.g:

<?php
$res = pg_query("SELECT table1.foo, table2.bar FROM table1 JOIN table2");
echo pg_field_table($res, 0); // Outputs 'table1'
echo pg_field_table($res, 1); // Outputs 'table2'
?>

However, be aware of a few easy 'gotchas':

1- If your query contains static values in its select-list, pg_field_table() will yield FALSE for those fields (because it was a static value, not one fetched from a table):

<?php
$res = pg_query("SELECT 'foo', bar FROM table");
echo pg_field_table($res, 0); // FALSE
echo pg_field_table($res, 1); // Outputs 'table'
?>

2- If you UNION two queries together from different tables, pg_field_table() will return FALSE for all fields:

<?php
$res = pg_query("(Select foo, bar from table1) UNION (Select foo, bar from table2)");
echo pg_field_table($res, 0); // FALSE
echo pg_field_table($res, 1); // FALSE
?>

down

giultar at gmail dot com ¶

4 years ago

this function return an OID even if your field comes from a view or a select but return FALSE if your field comes from an UNION select

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