Getting image from a DB

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Hi:

Has anybody here had to capture an image from a PostgreSQL Data Base =
using PHP?? I used a simple query: select photo from people where id =3D =
3, for instance. The problem is that when I write the image to disk it's =
not a valid image. I opened it using an HEX editor and saw that the =
question is that for each "strange" character, like =FF, it writes, for =
instance, \377, it is, the "\" symbol plus the character's numeric code. =
I guessed that there were some function for this situation but I =
couldn't find it. If you can't help me, I'll have to parse the whole =
image contents, with the subsequent performance impact.=20

PD: The image field is of type bytea,as you recommend me.
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Re: Getting image from a DB

Hi Felix,

I've not written an image specifically, but I have read/written byte=20
data which is all an image is.

Your PostgreSQL database column that holds the image should be of type=20
"bytea." Your PHP application must then use the following functions:

Writing to the database - http://uk2.php.net/pg_escape_bytea
Reading from the database -=20
http://uk2.php.net/manual/en/function.pg-unescape-bytea.php

Once you have unescaped the bytea data, you should then have your valid=20
set of bytes (your image) which you can either write to a temporary file=20
or stream directly to the user's browser from your application.

Regards,
Andy

F=E9lix S=E1nchez Rodr=EDguez wrote:
> Hi:
> =20
> Has anybody here had to capture an image from a PostgreSQL Data Base=20
> using PHP?? I used a simple query: select photo from people where id =3D=
=20
> 3, for instance. The problem is that when I write the image to disk=20
> it's not a valid image. I opened it using an HEX editor and saw that=20
> the question is that for each "strange" character, like =FF, it writes,=
=20
> for instance, \377, it is, the "\" symbol plus the character's numeric=20
> code. I guessed that there were some function for this situation but I=20
> couldn't find it. If you can't help me, I'll have to parse the whole=20
> image contents, with the subsequent performance impact.
> =20
> PD: The image field is of type bytea,as you recommend me.

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Re: Getting image from a DB

Well, using pg_unescape_bytea I was able to get the image. How can I stre=
am=20
it directly to the users's browser??


----- Original Message -----=20
From: "Andy Shellam"
To: "F=E9lix S=E1nchez Rodr=EDguez"
Cc:
Sent: Friday, May 08, 2009 8:26 AM
Subject: Re: [ADMIN] Getting image from a DB


> Hi Felix,
>
> I've not written an image specifically, but I have read/written byte da=
ta=20
> which is all an image is.
>
> Your PostgreSQL database column that holds the image should be of type=20
> "bytea." Your PHP application must then use the following functions:
>
> Writing to the database - http://uk2.php.net/pg_escape_bytea
> Reading from the database -=20
> http://uk2.php.net/manual/en/function.pg-unescape-bytea.php
>
> Once you have unescaped the bytea data, you should then have your valid=
=20
> set of bytes (your image) which you can either write to a temporary fil=
e=20
> or stream directly to the user's browser from your application.
>
> Regards,
> Andy
>
> F=E9lix S=E1nchez Rodr=EDguez wrote:
>> Hi:
>> Has anybody here had to capture an image from a PostgreSQL Data Base=20
>> using PHP?? I used a simple query: select photo from people where id =3D=
3,=20
>> for instance. The problem is that when I write the image to disk it's =
not=20
>> a valid image. I opened it using an HEX editor and saw that the questi=
on=20
>> is that for each "strange" character, like =FF, it writes, for instanc=
e,=20
>> \377, it is, the "\" symbol plus the character's numeric code. I guess=
ed=20
>> that there were some function for this situation but I couldn't find i=
t.=20
>> If you can't help me, I'll have to parse the whole image contents, wit=
h=20
>> the subsequent performance impact.
>> PD: The image field is of type bytea,as you recommend me.
>=20



--=20
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