Please note that a very old bug (#76548) has been fixed in 7.2.8.
Previously, pg_fetch_result did not fetch the next row if $row was omitted.
It is now well the case, so bad use of the function can now cause some bugs in your codes.
pg_fetch_result
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_fetch_result — Returns values from a result instance
Descrição
pg_fetch_result() returns the value of a particular row and field (column) in an PgSql\Result instance.
Nota:
This function used to be called pg_result().
Parâmetros
-
result -
Uma instância de PgSql\Result, retornada por pg_query(), pg_query_params() ou pg_execute() (entre outras).
-
row -
Row number in result to fetch. Rows are numbered from 0 upwards. If omitted, next row is fetched.
-
field -
A string representing the name of the field (column) to fetch, otherwise an int representing the field number to fetch. Fields are numbered from 0 upwards.
Valor Retornado
Boolean is returned as "t" or "f". All
other types, including arrays are returned as strings formatted
in the same default PostgreSQL manner that you would see in the
psql program. Database NULL
values are returned as null.
false is returned if row exceeds the number
of rows in the set, or on any other error.
Registro de Alterações
| Versão | Descrição |
|---|---|
| 8.3.0 |
row is now nullable.
|
| 8.1.0 |
O parâmetro result agora espera uma instância de PgSql\Result;
anteriormente, um resource era esperado.
|
Exemplos
Exemplo #1 pg_fetch_result() example
<?php
$db = pg_connect("dbname=users user=me") || die();
$res = pg_query($db, "SELECT 1 UNION ALL SELECT 2");
$val = pg_fetch_result($res, 1, 0);
echo "First field in the second row is: ", $val, "\n";
?>O exemplo acima produzirá:
First field in the second row is: 2
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User Contributed Notes 5 notes
ElDiablo ¶
6 years ago
newby_AT_nobletec_DOT_com ¶
22 years ago
Comment on boolean fields:
If you retrieve a boolean value from the PostgreSQL database, be aware that the value returned will be either the character 't' or the character 'f', not an integer. So, the statement
if (pg_fetch_result($rsRecords,0,'blnTrueFalseField')) {
echo "TRUE";
} else {
echo "FALSE";
}
will echo "TRUE" in either case (True or False stored in the field). In order to work as expected, do this instead:
if (pg_fetch_result($rsRecords,0,'blnTrueFalseField') == 't') {
echo "TRUE";
} else {
echo "FALSE";
}
Alan U. Kennington ¶
18 years ago
See bug #33809 http://bugs.php.net/bug.php?id=33809
Whether this really is a bug or a feature is not clear.
However, it is probably best to always put your column names in extra quotes.
$res = pg_query(...);
$colname = pg_field_name($res, $j);
pg_fetch_result($res, $i, "\"$colname\"");
Alan U Kennington ¶
18 years ago
In order to use upper case in pg_fetch_result column names, it is apparently necessary to include explicit quotation marks.
Thus when I do this sort of thing:
$res = pg_query(...);
$ncols = pg_num_fields($res);
for ($j = 0; $j < $ncols; ++$j) {
$colname[$j] = pg_field_name($res, $j);
$name = htmlspecialchars($colname[$j]);
print("Column $j name = \"$name\"\n");
$value = htmlspecialchars(pg_fetch_result($res, 0, $colname[$j]));
print("Column \"{$colname[$j]}\" value = \"$value\"\n");
}
I get this sort of thing:
[....]
Warning: pg_fetch_result() [function.pg-fetch-result]: Bad column offset specified in /.../view.php on line 247
Column 8 name = "VEC index"
Column "VEC index" value = ""
But if I change the $value line to this:
$value = htmlspecialchars(pg_fetch_result($res, 0, "\"$colname[$j]\""));
I get this:
[...]
Column 8 name = "VEC index"
Column "VEC index" value[0] = "47"
In my opinion, pg_fetch_result(...) should use the quotes already. In other words, this may be a bug in the PHP postgres library. It does not seem to be a documented feature of pg_fetch_result() although the postgresql manual documents it under "SQL syntax", "Lexical structure".
PHP version 5.1.4.
psql version 8.1.4.
Akbar ¶
20 years ago
Use can use pg_fetch_result when getting a value (like a smallint as in this example) returned by your stored procedure
<?php
$pgConnection = pg_connect("dbname=users user=me");
$userNameToCheckFor = "metal";
$result = pg_query($pgConnection, "SELECT howManyUsersHaveThisName('$userNameToCheckFor')");
$count = pg_fetch_result($result, 0, 'howManyUsersHaveThisName');
?>
