(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_field_size — 返回指定字段的内部存储大小
pg_field_size() 返回指定 PostgreSQL result 中字段编号的内部存储大小（以字节为单位）。
注意:
本函数以前的名字为 pg_fieldsize()。
resultPgSql\Result 实例，由 pg_query()、pg_query_params() 或者 pg_execute()（等）返回。
field字段编号，从 0 开始。
内部字段存储大小（以字节为单位）。-1 表示可变长度字段。
| 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 #1 获取字段信息
<?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";
}
?>以上示例会输出：
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