pg_escape_bytea
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_escape_bytea — 转义字符串以插入到 bytea 字段
说明
pg_escape_bytea() 转义 bytea 数据类型的字符串。返回转义后的字符串。
注意:
当
SELECTbytea 类型时，PostgreSQL 返回前缀为“\”的八进制字节值（例如 \032）。用户需要手动转换为二进制格式。本函数需要 PostgreSQL 7.2 及其更高版本。在 PostgreSQL 7.2.0 和 7.2.1 版中，如果使用了多字节支持，必须强制转换 bytea 类型。即
INSERT INTO test_table (image) VALUES ('$image_escaped'::bytea);，在 PostgreSQL 7.2.2 及其更高版本不需要强制转换。异常情况是当客户端和后端字符编码不匹配时，可能会有多字节流错误。然后用户必须强制转换 bytea 以避免此错误。
参数
connection-
An PgSql\Connection instance. When
connectionis unspecified, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().警告As of PHP 8.1.0, using the default connection is deprecated.
data-
包含要插入到 bytea 列中的文本或二进制数据的 string。
返回值
包含转义数据的 string。
更新日志
| 版本 | 说明 |
|---|---|
| 8.1.0 |
现在 connection 参数接受 PgSql\Connection
实例，之前接受 resource。
|
示例
示例 #1 pg_escape_bytea() 示例
<?php
// 连接到数据库
$dbconn = pg_connect('dbname=foo');
// 读入二进制文件
$data = file_get_contents('image1.jpg');
// 转义二进制数据
$escaped = pg_escape_bytea($data);
// 将其插入数据库
pg_query("INSERT INTO gallery (name, data) VALUES ('Pine trees', '{$escaped}')");
?>
＋添加备注
用户贡献的备注 8 notes
ynzhang from lakeheadu of ca ¶
16 years ago
The reason pg_unescape_bytea() do not exactly reproduce the binary data created by pg_escape_bytea() is because the backslash \ and single quote ' are double escaped by the pg_escape_bytea() function. This will lead to image seems corrupted when retrieve from the bytea field. The proper way to escape&unescape a binary string into a PG bytea field as follow:
<?php
$escaped_data = str_replace(array("\\\\", "''"), array("\\", "'"), pg_escape_bytea($data));
/* and later unescape the escaped data from the bytea field with following to get the original binary data */
$original_data = pg_unescape_bytea($escaped_data));
?>
more details at: http://archives.postgresql.org/pgsql-php/2007-02/msg00014.php
Hayley Watson ¶
7 years ago
PostgreSQL 9.0 introduced a new hexadecimal-based representation for bytea data that is preferred over the escaping mechanism implemented by this function.
<?php
function pg_escape_byteahex($binary)
{
return "E'\\\\x".bin2hex($binary)."'";
}
?>
Mike-RaWare ¶
14 years ago
To prevent any problems with encoding you could use hexadecimal or base64 input to save and retrieve data to the database:
<?php
// Connect to the database
$dbconn = pg_connect( 'dbname=foo' );
// Read in a binary file
$data = file_get_contents( 'image1.jpg' );
// Escape the binary data
$escaped = bin2hex( $data );
// Insert it into the database
pg_query( "INSERT INTO gallery (name, data) VALUES ('Pine trees', decode('{$escaped}' , 'hex'))" );
// Get the bytea data
$res = pg_query("SELECT encode(data, 'base64') AS data FROM gallery WHERE name='Pine trees'");
$raw = pg_fetch_result($res, 'data');
// Convert to binary and send to the browser
header('Content-type: image/jpeg');
echo base64_decode($raw);
?>
Mocha ¶
21 years ago
to unescape_bytea use stripcslashes(). If you need to escape bytea and don't have pg_escape_bytea() function then use:
<?php
function escByteA($binData) {
/**
* \134 = 92 = backslash, \000 = 00 = NULL, \047 = 39 = Single Quote
*
* str_replace() replaces the searches array in order. Therefore, we must
* process the 'backslash' character first. If we process it last, it'll
* replace all the escaped backslashes from the other searches that came
* before.
*/
$search = array(chr(92), chr(0), chr(39));
$replace = array('\\\134', '\\\000', '\\\047');
$binData = str_replace($search, $replace, $binData);
return $binData;
//echo "<pre>$binData</pre>";
//exit;
}
?>
tabflo at gmx dot at ¶
6 months ago
this method des the same as pg_escape_bytea have fun with it:
public function escape_bytea($data) {
$escaped = '';
for ($i = 0; $i < strlen($data); $i++) {
$char = $data[$i];
$ascii = ord($char);
$escaped.= ($ascii < 32 || $ascii > 126 ? sprintf('\\%03o', $ascii) : ($char == '\\' ? '\\\\' : $char) );
}
return $escaped;
}
Michael ¶
10 years ago
using pg_escape_bytea without 'E' escape tag
<?php
// Die Binärdaten maskieren
$escaped = pg_escape_bytea($data);
// und in die Datenbank einfügen (falsch/wrong)
pg_query("INSERT INTO gallery (name, data) VALUES ('Pine trees', E'$escaped')");
// und in die Datenbank einfügen (richtig/right)
pg_query("INSERT INTO gallery (name, data) VALUES ('Pine trees', '$escaped')");
?>
gglockner AT NOSPAMdwaffler DOT com ¶
15 years ago
If you're getting errors about nonstandard use of \\ in a string literal, then you need to escape the encoded bytea as follows:
<?php
$escaped = pg_escape_bytea($data);
pg_query("INSERT INTO gallery (name, data) VALUES ('Pine trees', E'$escaped'::bytea)");
?>
php at tobias dot olsson dot be ¶
22 years ago
if you need to change back bytea from the db to normal data, this will do that:
<?php
function pg_unescape_bytea($bytea) {
return eval("return \"".str_replace('$', '\\$', str_replace('"', '\\"', $bytea))."\";");
}
// use like this
$rs = pg_query($conn, "SELECT image from images LIMIT 1");
$image = pg_unescape_bytea(pg_fetch_result($rs, 0, 0));
?>
/Tobias备份地址：http://www.lvesu.com/blog/php/function.pg-escape-bytea.php