oci_field_scale

(PHP 5, PHP 7, PHP 8, PECL OCI8 >= 1.1.0)

oci_field_scale — フィールドの桁数を問い合わせる

説明

oci_field_scale(resource $statement, string|int $column): int|false

column に対応するカラムの桁数を返します。

FLOAT 型カラムの精度は 0 でなく桁数は -127 となります。もし精度が 0 の場合、カラムは NUMBER 型、そうでなければ NUMBER(精度, 桁数) となります。

パラメータ

statement: 有効な OCI ステートメント ID。
column: フィールド番号 (1 から始まる) あるいは名前のいずれか。

戻り値

桁数を表す整数値を返します。失敗した場合に false を返します

例

例1 oci_field_scale() の例

<?php

// 以下のテーブルを用意します
//   CREATE TABLE mytab (c1 NUMBER, c2 FLOAT, c3 NUMBER(4), c4 NUMBER(5,3));

$conn = oci_connect("hr", "hrpwd", "localhost/XE");
if (!$conn) {
    $m = oci_error();
    trigger_error(htmlentities($m['message']), E_USER_ERROR);
}

$stid = oci_parse($conn, "SELECT * FROM mytab");
oci_execute($stid, OCI_DESCRIBE_ONLY); // 行をフェッチしない場合は OCI_DESCRIBE_ONLY を使います

$ncols = oci_num_fields($stid);
for ($i = 1; $i <= $ncols; $i++) {
    echo oci_field_name($stid, $i) . " " 
        . oci_field_precision($stid, $i) . " " 
        . oci_field_scale($stid, $i) . "<br>\n";
}

// 出力は
//   C1    0 -127
//   C2  126 -127
//   C3    4    0
//   C4    5    3

oci_free_statement($stid);
oci_close($conn);

?>

参考

oci_field_precision() - フィールドの精度を問い合わせる
oci_field_type() - フィールドのデータ型の名前を返す

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User Contributed Notes 1 note

down

VLroyrenn ¶

7 years ago

If you're converting SQL values to their respective float and int values based on scale and precision like I am, there's a catch, here.

This is a slimmed-down version of the conversion logic I'm using :

<?php
$col = [
    'id' => $field_id,
    'name' => oci_field_name($statement, $field_id),
    'type' => oci_field_type($statement, $field_id),
    'scale' => oci_field_scale($statement, $field_id);
    'precision' => oci_field_precision($statement, $field_id);
]

$str_data = oci_result($statement, $field_id)

switch($col['type']) {
    case 'NUMBER':
        if ($col['precision'] !== 0 && $col['scale'] === -127) {
            // A binary float
            $data = floatval($str_data);
        } else if($col['scale'] === 0) {
            // An integer
            $data = intval($str_data);
        } else {
            // A fixed-point decimal number, which has no equivalent in PHP, so float
            $data = floatval($str_data);
        }
        
        break;
    
    default:
        $data = $str_data;
        break;
}

echo("{$col['name']} : $str_data ({$col['type']} ({$col['precision']}, {$col['scale']})) -> $data\n");
?>

What the doc doesn't say is that any number column that was defined without a scale parameter counts as a plain NUMBER(), which always has a precision of 0 and a scale of -127, so they get interpreted as floats even when they should be integers.

What the doc also doesn't say is that __all analytics functions that return numbers return a plain NUMBER()__, so something like COUNT(*), RANK() or FIRST_VALUE(foo) is still going to net you a float.

Be careful with these if you have any type-sensitive code that relies on those values (I'm personally very fond of using type-hinting and strict_types = 1).

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