pg_num_fields

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

pg_num_fields返回结果中字段的数量

说明

pg_num_fields(PgSql\Result $result): int

pg_num_fields() 返回 PgSql\Result 实例中字段(列)的数量。

注意:

本函数以前的名字为 pg_numfields()

参数

result

PgSql\Result 实例,由 pg_query()pg_query_params() 或者 pg_execute()(等)返回。

返回值

结果中的字段(列)的数量。错误时返回 -1。

更新日志

版本 说明
8.1.0 现在 result 参数接受 PgSql\Result 实例,之前接受 resource

示例

示例 #1 pg_num_fields() 示例

<?php
$result
= pg_query($conn, "SELECT 1, 2");

$num = pg_num_fields($result);

echo
$num . " field(s) returned.\n";
?>

以上示例会输出:

2 field(s) returned.

参见

添加备注

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-1
mark at redbrick dot dcu dot ie
22 years ago
Here is a simple example for using pg_num_feilds, pg_num_rows and pg_result together.  I'm simply SELECTing * from a table named markie on the current pg_connect().  <?php    $pgsql_conn = pg_connect("dbname=mark host=localhost");    if (!$pgsql_conn) {        print pg_last_error($pgsql_conn);        exit;    }    $results = pg_query($pgsql_conn, "SELECT * FROM markie");    echo "<table border=1>\n";    for($lt = 0; $lt < pg_num_rows($results); $lt++) {        echo "<tr>\n";        for($gt = 0; $gt < pg_num_fields($results); $gt++) {            echo "<td>" . pg_result($results, $lt, $gt) . "</td>\n";        }        echo "</tr>\n";    }    echo "</table>\n";    pg_close($pgsql_conn);?>This code snippet will print out the rows and columns into a HTML table.Regards,  --mark
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