pg_field_size

(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

说明

pg_field_size(PgSql\Result $result, int $field): int

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()

参数

result

PgSql\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。

返回值

内部字段存储大小(以字节为单位)。-1 表示可变长度字段。

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 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

参见