Dealing with eacute and other special characters using Oracle, PHP and Oci8 - php

Question

Hi I am trying to store names into an Oracle database and fetch them back using PHP and oci8.
However, if I insert the é directly into the Oracle database and use oci8 to fetch it back I just receive an e
Do I have to encode all special characters (including é) into html entities (ie: é) before inserting into database ... or am I missing something ?
Thx
UPDATE: Mar 1 at 18:40
found this function:
http://www.php.net/manual/en/function.utf8-decode.php#85034
function charset_decode_utf_8($string) {
if(#!ereg("[\200-\237]",$string) && #!ereg("[\241-\377]",$string)) {
return $string;
}
$string = preg_replace("/([\340-\357])([\200-\277])([\200-\277])/e","'&#'.((ord('\\1')-224)*4096 + (ord('\\2')-128)*64 + (ord('\\3')-128)).';'",$string);
$string = preg_replace("/([\300-\337])([\200-\277])/e","'&#'.((ord('\\1')-192)*64+(ord('\\2')-128)).';'",$string);
return $string;
}
seems to work, although not sure if its the optimal solution
UPDATE: Mar 8 at 15:45
Oracle's character set is ISO-8859-1.
in PHP I added:
putenv("NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P1");
to force the oci8 connection to use that character set.
Retrieving the é using oci8 from PHP now worked ! (for varchars, but not CLOBs had to do utf8_encode to extract it )
So then I tried saving the data from PHP to Oracle ... and it doesnt work..somewhere along the way from PHP to Oracle the é becomes a ?
UPDATE: Mar 9 at 14:47
So getting closer.
After adding the NLS_LANG variable, doing direct oci8 inserts with é works.
The problem is actually on the PHP side.
By using ExtJs framework, when submitting a form it encodes it using encodeURIComponent.
So é is sent as %C3%A9 and then re-encoded into é.
However it's length is now 2 (strlen($my_sent_value) = 2) and not 1.
And if in PHP I try: $my_sent_value == é = FALSE
I think if I am able to re-encode all these characters in PHP back into lengths of byte size 1 and then inserting them into Oracle, it should work.
Still no luck though
UPDATE: Mar 10 at 11:05
I keep thinking I am so close (yet so far away).
putenv("NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P9"); works very sporadicly.
I created a small php script to test:
header('Content-Type: text/plain; charset=ISO-8859-1');
putenv("NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P9");
$conn= oci_connect("user", "pass", "DB");
$stmt = oci_parse($conn, "UPDATE temp_tb SET string_field = '|é|'");
oci_execute($stmt, OCI_COMMIT_ON_SUCCESS);
After running this once and loggin into the Oracle Database directly I see that STRING_FIELD is set to |¿|. Obviously not what I had come to expect from my previous experience.
However, if I refresh that PHP page twice quickly.... it worked !!!
In Oracle I correctly saw |é|.
It seems like maybe the environment variable is not being correctly set or sent in time for the first execution of the script, but is available for the second execution.
My next experiment is to export the variable into PHP's environment, however, I need to reset Apache for that...so we'll see what happens, hopefully it works.

Answer 1

I presume you are aware of these facts:
There are many different character sets: you have to pick one and, of course, know which one you are using.
Oracle is perfectly capable of storing text without HTML entities (é). HTML entities are used in, well, HTML. Oracle is not a web browser ;-)
You must also know that HTML entities are not bind to a specific charset; on the contrary, they're used to represent characters in a charset-independent context.
You indistinctly talk about ISO-8859-1 and UTF-8. What charset do you want to use? ISO-8859-1 is easy to use but it can only store text in some latin languages (such as Spanish) and it lacks some common chars like the € symbol. UTF-8 is trickier to use but it can store all characters defined by the Unicode consortium (which include everything you'll ever need).
Once you've taken the decision, you must configure Oracle to hold data in such charset and choose an appropriate column type. E.g., VARCHAR2 is fine for plain ASCII, NVARCHAR2 is good for UTF-8.

Answer 2

This is what I finally ended up doing to solve this problem:
Modified the profile of the daemon running PHP to have:
NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P1
So that the oci8 connection uses ISO-8859-1.
Then in my PHP configuration set the default content-type to ISO-8859-1:
default_charset = "iso-8859-1"
When I am inserting into an Oracle Table via oci8 from PHP, I do:
utf8_decode($my_sent_value)
And when receiving data from Oracle, printing the variable should just work as so:
echo $my_received_value
However when sending that data over ajax I have had to use:
utf8_encode($my_received_value)

Answer 3

If you really cannot change the character set that oracle will use then how about Base64 encoding your data before storing it in the database. That way, you can accept characters from any character set and store them as ISO-8859-1 (because Base64 will output a subset of the ASCII character set which maps exactly to ISO-8859-1). Base64 encoding will increase the length of the string by, on average, 37%
If your data is only ever going to be displayed as HTML then you might as well store HTML entities as you suggested, but be aware that a single entity can be up to 10 characters per unencoded character e.g. ϑ is ϑ

Answer 4

I had to face this problem : the LatinAmerican special characters are stored as "?" or "¿" in my Oracle database ... I can't change the NLS_CHARACTER_SET because we're not the database owners.
So, I found a workaround :
1) ASP.NET code
Create a function that converts string to hexadecimal characters:
public string ConvertirStringAHex(String input)
{
Encoding encoding = System.Text.Encoding.GetEncoding("ISO-8859-1");
Byte[] stringBytes = encoding.GetBytes(input);
StringBuilder sbBytes = new StringBuilder(stringBytes.Length);
foreach (byte b in stringBytes)
{
sbBytes.AppendFormat("{0:X2}", b);
}
return sbBytes.ToString();
}
2) Apply the function above to the variable you want to encode, like this
myVariableHex = ConvertirStringZHex( myVariable );
In ORACLE, use the following:
PROCEDURE STORE_IN_TABLE( iTEXTO IN VARCHAR2 )
IS
BEGIN
INSERT INTO myTable( SPECIAL_TEXT )
VALUES ( UTL_RAW.CAST_TO_VARCHAR2(HEXTORAW( iTEXTO ));
COMMIT;
END;
Of course, iTEXTO is the Oracle parameter which receives the value of "myVariableHex" from ASP.NET code.
Hope it helps ... if there's something to improve pls don't hesitate to post your comments.
Sources:
http://www.nullskull.com/faq/834/convert-string-to-hex-and-hex-to-string-in-net.aspx
https://forums.oracle.com/thread/44799

Answer 5

If you have different charsets between the server side code (php in this case) and the Oracle database, you should set server side code charset in the Oracle connection, then Oracle made the conversion.
Example: Let's assume:
php charset utf-8 (default).
Oracle charset AMERICAN_AMERICA.WE8ISO8859P1
In the connection to Oracle made by php you should set UTF8 (third parameter).
oci_pconnect("USER", "PASS", "URL"),"UTF8");
Doing this, you write code in utf-8 (not doing any conversion at all) and get utf-8 from the database through this connection.
So you could write something like SELECT * FROM SOME_TABLE WHERE TEXT = 'SOME TEXT LIKE áéíóú Ñ' and also get utf-8 text as a result.
According to the php documentation, by default, Oracle client (oci_pconnect) takes the NLS_LANG environment variable from the Operating system. Some debian based systems has no NLS_LANG enviromental variable, so I think Oracle client use it's own charset (AMERICAN_AMERICA.WE8ISO8859P1) if we don't specify the third parameter.