I have the above table: tblCompInfo, the product_id value is not 100% accurate and I need to fix it. I have total of 543847 total row with 25 different company and 12 different products.
now, The URL is 100% accurate and as you can see from the image I have highlighted with RED which means they are wrong and GREEN which is what it should be updated to.
TASK:
I need to update Product_id by parsing through URL and getting the INTEGER and checking it with product table, if its a product, assign the value else assign 0.
SOLUTION:
I got two solution in my head:
1. EXPORT the entire DATA to EXCEL CVS, change it and UPLOAD it to DATABASE. which means my entire week will be working with EXCEL only.
2. Since I have laravel framework: I can make a function in PHP and get the DATA company wise and UPDATE the table in a foreach loop with condition.
PROBLEM:
So, to make my life easy, I made the PHP function with a simple solution and it works BUT I get MEMORY ALLOCATION PROBLEM.
$companyID = ??;
$tblCompInfos = tblCompInfo::where('company_id', '=', $companyID)->get();
foreach($tblCompInfos as $tblCompInfo)
{
$actual_link = $tblCompInfo->url;
$pathlink = parse_url($actual_link, PHP_URL_PATH);
$product_id_from_url = preg_replace("/[^0-9]/", "" , $pathlink);
$FindIfItsInProductTable = Product::find($product_id_from_url);
$real_product_id = $FindIfItsInProductTable == null ? 0 : $product_id_from_url;
DB::table('tblCompInfo')->where('company_id', '=', $companyID)->where('url', '=', $tblCompInfo->url)->update(array(
'product_id' => $real_product_id,
));
echo $actual_link."-".$real_product_id."=".$tblCompInfo->product_id."<br>";
}
if it was a local server, I would have update my PHP.ini with more memory and do the job.
However, I have a LIVE server and it has to be done in the live server and I have no control or power over PHP.ini.
What to do? How can I do it easily that I will not get a memory issue?
Please help if anyone?
Try this :
UPDATE [table_name] SET product_id = CONVERT(SUBSTR(url, LOCATE('products/', url)+9, LOCATE('/compare',url)-LOCATE('products/', url)+9),UNSIGNED INTEGER)
But this will only works if every url field has suffix as /compare
if you use MariaDB you can use REGEXP_REPLACE to do the changes like
UPDATE your_table
SET url = REGEXP_REPLACE(url,'[0-9]+',Product_id)
WHERE Product_id > 0;
sample
MariaDB [your_schema]> SELECT REGEXP_REPLACE('http://example.com/products/12/compare','[0-9]+','99');
+--------------------------------------------------------------------+
| REGEXP_REPLACE('http://example.com/products/12/compare','[0-9]+','99') |
+--------------------------------------------------------------------+
| http://example.com/products/99/compare |
+--------------------------------------------------------------------+
1 row in set (0.00 sec)
MariaDB [your_schema]>
I have a pretty odd idea but it can work.
Look at that query :
SELECT
'http://example.com/products/12/compare' as url,
'http://example.com/products/' as check1,
'http://example.com/termsets/' as check2,
'http://example.com/products/12/compare' REGEXP 'http://example.com/products/' as regexp_check1, -- check 1
SUBSTRING('http://example.com/products/12/compare', LOCATE('http://example.com/products/','http://example.com/products/12/compare')+LENGTH('http://example.com/products/'),1 ) as test1,
SUBSTRING('http://example.com/products/12/compare', LOCATE('http://example.com/products/','http://example.com/products/12/compare')+LENGTH('http://example.com/products/'),1 ) REGEXP "^[0-9]+$" as test1_only_num,
SUBSTRING('http://example.com/products/12/compare', LOCATE('http://example.com/products/','http://example.com/products/12/compare')+LENGTH('http://example.com/products/'),2 ) as test11,
SUBSTRING('http://example.com/products/12/compare', LOCATE('http://example.com/products/','http://example.com/products/12/compare')+LENGTH('http://example.com/products/'),1 ) REGEXP "^[0-9]+$" as test11_only_num,
SUBSTRING('http://example.com/products/12/compare', LOCATE('http://example.com/products/','http://example.com/products/12/compare')+LENGTH('http://example.com/products/'),3 ) as test111,
SUBSTRING('http://example.com/products/12/compare', LOCATE('http://example.com/products/','http://example.com/products/12/compare')+LENGTH('http://example.com/products/'),1 ) REGEXP "^[0-9]+$" as test111_only_num;
Result :
+----------------------------------------+------------------------------+------------------------------+---------------+-------+----------------+--------+-----------------+---------+------------------+
| url | check1 | check2 | regexp_check1 | test1 | test1_only_num | test11 | test11_only_num | test111 | test111_only_num |
+----------------------------------------+------------------------------+------------------------------+---------------+-------+----------------+--------+-----------------+---------+------------------+
| http://example.com/products/12/compare | http://example.com/products/ | http://example.com/termsets/ | 1 | 1 | 1 | 12 | 1 | 12/ | 0 |
+----------------------------------------+------------------------------+------------------------------+---------------+-------+----------------+--------+-----------------+---------+------------------+
Url, check1 and check2 are just to display the variables I'm using. It's a main ID, the query is not usable that way of course.
Logic with check1
You check with a REGEX if check1 is present in your URL. If yes, regexp_check1 is 1, else it's 0.
ONLY if regexp_check1 is 1, then you SUBSTRING your URL to take the part that is located AFTER the check1 sentence. You take the first character AFTER (test1), then the two characters AFTER (test11), the three characters AFTER (test111) etc.. until the max length your ID_PRODUCT can be (6 or 7 for example).
You REGEX the SUBSTR you isolated to check if they are numeric only (test1 is numeric, test11 is numeric only, test111 is not numeric only.
Then you know that the content of test11 is your ID
Then you do the same thing with check2 if regexp_check1 was 0, and with an eventual check3 (which would contain http://www.comadso.dk/products/ for example), and for every beginning you can have.
Maybe my idea is a shitty one, but hey if it's seem dumb but works, it's not dumb !
I have this code:
$tierHosts['host'] = isset($host['name']) ? $host['name'] : $host;
It's working fine in PHP 5.5, but in PHP 5.3 the condition returns true while $host contains a string like pjba01. It returns the first letter of $tierHosts['host'], that is, p.
What's so wrong with my code?
You can access strings like an array and prior PHP 5.4 offsets like your name were silently casted to 0, means you accessed the first character of that string:
character | p | j | b | a | 0 | 1 |
-----------------------------------
index | 0 | 1 | 2 | 3 | 4 | 5 |
After 5.3 such offsets will throw a notice, as you can also read in the manual:
As of PHP 5.4 string offsets have to either be integers or integer-like strings, otherwise a warning will be thrown. Previously an offset like "foo" was silently cast to 0.
I am running these two printf() functions and little bit confused with the output generated by them.
printf("%0.4f",3467);
It outputs - 3467.0000. In first parameter that is 0.4f 4 is understood as it represents 4 zeros after decimal but I am not sure about the 0 as I changed it to 1,2,3 it remains same. So what does it do ?
printf("%1.6u\n", -32);
While running this, I am getting 4294967264 what exactly does this number refers too ?
Before asking I checked printf() link whick is referring to sprintf() for parameter look up, but unable to find something on this.
The 0 in %0.4f is the minimum length the output will have when the value is formatted. In your case you will not see any difference in output unless you change it to 10 or above as the output like that will always be 3467.0000. If you change the 0 to 15 you will get one blank in front of the formatted output:
printf("%15.4f", 3467);
3467.0000
| | |
1 10 5
In your browser you will not see the extra blanks, but if you additionally tell it to use a dot as the fill-character you will see it:
printf("%'.15.4f", 3467);
......3467.0000
| | |
1 10 5
As for your second question. You are formatting a signed value as unsigned output. -32 as unsigned 32 bit integer is FFFFFFE0. If you tell printf to output that as unsigned you will get the unsigned value of FFFFFFE0 which is 4294967264.
For example, this is my table, which is called example:
--------------------------
| id | en_word | zh_word |
--------------------------
| 1 | Internet| 互联网 |
--------------------------
| 2 | Hello | 你好 |
--------------------------
and so on...
And I tried using this SQL Query:
SELECT * FROM `example` WHERE LENGTH(`zh_word`) = 3
For some reason, it wouldn't give me three, but would give me a lot of single letter characters.
Why is this? Can this be fixed? I tried this out in PhpMyAdmin.
But when I did it with JavaScript:
"互联网".length == 3; // true
And it seems to work fine. So how come it doesn't work?
you should use CHAR_LENGTH instead of LENGTH
LENGTH() returns the length of the string measured in bytes.
CHAR_LENGTH() returns the length of the string measured in characters.
LENGTH returns length in bytes (and chinese is multibyte)
Use CHAR_LENGTH to get length in characters
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_char-length
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_length
I was wonder what is the maximum length of the timezone settings in PHP? I'm storing the string in a database, and would like to keep the length as short as possible, but i see timezones like "Canada/East-Saskatchewan", which goes beyond our current limit.
If I could just get a list of all the supported timezone string, I can sort them, but they are currently split on to several different pages.
linky: http://www.php.net/manual/en/timezones.php
Edit June 2021 Answer is 64. Why? That's the width of the column used in MySQL to store those timezone name strings.
The zoneinfo database behind those time zone strings just added new prefixes. To America/Argentina/ComodRivadavia, formerly the longest timezone string, they added posix/America/Argentina/ComodRivadavia and right/America/Argentina/ComodRivadavia, both with a length of 38. This is up from 32, the previous longest string.
And here is the complete PHP code to find that:
<?php
$timezone_identifiers = DateTimeZone::listIdentifiers();
$maxlen = 0;
foreach($timezone_identifiers as $id)
{
if(strlen($id) > $maxlen)
$maxlen = strlen($id);
}
echo "Max Length: $maxlen";
/*
Output:
Max Length: 32
*/
?>
The Olson database — available from ftp://ftp.iana.org/tz/releases/ or http://www.iana.org/time-zones (but see also http://www.twinsun.com/tz/tz-link.htm* and http://en.wikipedia.org/wiki/Tz_database) — is the source of these names. The documentation in the file Theory includes a description of how the zone names are formed. This would help you establish how long names can be.
The longest 'current' names are 30 characters (America/Argentina/Buenos_Aires,
America/Argentina/Rio_Gallegos, America/North_Dakota/New_Salem); the longest 'backwards compatibility' name is 32 characters (America/Argentina/ComodRivadavia).
* Note that the TwinSun site has not been updated for some time and has some outdated links (such as suggesting that the Olson database is available from ftp://ftp.elsie.nci.nih.gov — it is now available from IANA instead).
From the manual:
<?php
$timezone_identifiers = DateTimeZone::listIdentifiers();
for ($i=0; $i < 5; $i++) {
echo "$timezone_identifiers[$i]\n";
}
?>
If you are using MySQL with PHP, consider that MySQL already stores Olson timezone names in the "mysql" system database, in a table called "time_zone_name", in a column called "name". One option is to choose the length of your column to match the length that MySQL uses. In MySQL 5.7, the timezone name length is 64 characters. To determine the length in use on your MySQL installation, follow the example below:
mysql> use mysql
Database changed
mysql> describe time_zone_name;
+--------------+------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------------+------+-----+---------+-------+
| Name | char(64) | NO | PRI | NULL | |
| Time_zone_id | int(10) unsigned | NO | | NULL | |
+--------------+------------------+------+-----+---------+-------+
2 rows in set (0.01 sec)