In the admin section of my website there is a button that extracts an Excel file with data from my database. In reality, it is an Excel file that is created upon clicking the button using PEAR. I use an SQL query to get the information necessary from my SQL Server 2008 database.
One of the columns named 'number1' contains a number ranging from 1-9999. I have been looking for a way to have it put zeros in front of the numbers when it doesnt have 4 digits already, but I've had no luck until now. For example, if the number in the database is 12, I would like it to show as 0012 in my Excel sheet.
currently the code used is the following:
if ($j == 15){
$worksheet->write($variable1, $j , $variable2[$i][$j], $text222);
}
where $variable1 = 0; $variable2 = ("my sql query")
Your help is appreciated.
EDIT: ANSWER(S)
$number = str_pad($value, 4, '0', STR_PAD_LEFT);
OR
JAGAnalyst's answer, the one I actually used in my code.
Alternatively, you can also edit your SQL query to return a four-character text string instead of a number, including the replacement function, i.e.
, CASE
WHEN Len(number1) = 1 THEN '000' + CAST(number1 AS VARCHAR(4))
WHEN Len(number1) = 2 THEN '00' + CAST(number1 AS VARCHAR(4))
WHEN Len(number1) = 3 THEN '0' + CAST(number1 AS VARCHAR(4))
ELSE CAST(number1 AS VARCHAR(4))
END AS NEW
This will actually alter the value that is extracted, rather than simply changing the format.
Related
So i want to add some info to the existing info in mysql, so i use this kind of code:
SET date = $alp + number
WHERE id=15 ');
$ES->execute();
$ES->close();
here i got 2 little problems:
When i type an integer, it adds them together. Date is preset as an integer, and i type $alp as 3 for example.
Instead of showing 3 4, it shows like 7. It adds 2 numbers. How do i prevent that? I just want them to stay side by side. Anohter problem when i try to put string, that is kind of fair because letter plus number doesnt work. But how do i make the command so the sql gets it as putting it together and not adding them (doing math i mean). would appriciate answers!
Use CONCAT to "string" the number together in MySQL.. Like so:
SET date = CONCAT($alp, ' number')
Your output will be 3 4
And to concatenate a string in php you would do something like:
$alp = '3';
$alp .= ' 4';
echo $alp;
// output: 3 4
I'm using PHP 7 with Phalcon PHP and I'm trying to create a method to generate a booking number. Here is my current method :
public function generateNumber($company_code) {
// Build the prefix : COMPANY20190820
$prefix = $company_code . date('Ymd');
// It's like SELECT count(*) FROM bookings WHERE number LIKE 'COMPANY20190820%'
$counter = Bookings::count(array(
"number LIKE :number:",
"bind" => array('number' => $prefix.'%')
));
// Concat prefix with bookings counter with str_pad
// COMPANY20190820 + 005 (if 4 bookings in DB)
$booking_number = $prefix . str_pad($counter + 1, 3, 0, STR_PAD_LEFT);
// Return COMPANY20190820005
return $booking_number;
}
So I have a problem because sometime I have to delete 1 or multiple bookings so I can get :
COMPANY20190820001
COMPANY20190820002
COMPANY20190820005
COMPANY20190820006
COMPANY20190820007
And I need to add after the last in my DB so here 007, because I can get duplicated booking number if I count like that.
So how can I do to take the last and increment according the last booking number of the current day ?
You need to rethink what you want to do here as it will never work that way.
As I see it you have at least two options:
Use an auto-increment id and use that in combination with the prefix
Use a random fairly unique string (e.g. UUID4)
You should never manually try to get the current maximum id as that may and most likely will at some point result in race conditions and brittle code as a result of that.
So I found a solution, maybe there is a better way to do that but my function works now:
public function generateNumber($company_code) {
// Build the prefix : COMPANY20190820
$prefix = $company_code . date('Ymd');
// Get the last booking with the today prefix
// e.g : COMPANY20190820005
$last_booking = Bookings::maximum(array(
"column" => "number",
"number LIKE :number:",
"bind" => array('number' => $prefix.'%')
));
// Get the last number by removing the prefix (e.g 005)
$last_number = str_replace($prefix, "", $last_booking);
// trim left 0 if exist to get only the current number
// cast to in to increment my counter (e.g 5 + 1 = 6)
$counter = intval(ltrim($last_number, "0")) + 1;
// Concat prefix + counter with pad 006
$booking_number = $prefix . str_pad($counter, 3, 0, STR_PAD_LEFT);
// Return COMPANY20190820006
return $booking_number;
}
I reckon that the use case you describe does not justify the hassle of writing a custom sequence generator in PHP. Additionally, in a scenario where booking deletion is expected to happen, ID reusing feels more a bug than a feature, so your system should store a permanent counter to avoid reusing, making it less simple. Don't take me wrong, it can be done and it isn't rocket science, but it's time and energy you don't need to spend.
Your database engine surely has a native tool to generate autoincremented primary keys, with varying names and implementations (SQL Server has identity, Oracle has sequences and identity, MySQL has auto_increment...). Use that instead.
Keep internal data and user display separated. More specifically, don't use the latter to regenerate the former. Your COMPANY20190820007 example is trivial to compose from individual fields, either in PHP:
$booking_number = sprintf('%s%s%03d',
$company_code,
$booking_date->format('Ymd'),
$booking_id
);
... or in SQL:
-- This is MySQL dialect, other engines use their own variations
SELECT CONCAT(company_code, DATE_FORMAT(booking_date, '%Y%m%d'), LPAD(booking_id, 3, '0')) AS booking_number
FROM ...
You can (and probably should) save the resulting booking_number, but you cannot use it as source for further calculations. It's exactly the same case as dates: don't need to store dates in plain English in order to eventually display them to the end-user and you definitively don't want to parse English dates back to actual dates in order to do anything else beyond printing.
You also mention the possibility of generating long pure-digit identifiers, as Bookings.com does. There're many ways to do it and we can't know which one they use, but you may want to considering generating a numeric hash out of your auto-incremented PK via integer obfuscation.
you could split your database field in two parts, so you hold the prefix and the counter separately.
then, you simply select the highest counter for your desired prefix and increment that one.
if you can't change the table structure, you could alternatively order by the id descendingly and select the first. then you can extract its counter manually. keep in mind you should pad the numbers then, or you get #9 even if #10 exists.
if padding is not an option, you can direct the database to replace your prefix. that way, you can cast the remaining string to a number and let the database sort - this will cost some performance, though, so keep the amount of records low.
I have an int field in a MySQL database that is progressively going up every time a user of the database performs a specific action so it's going up in increments of 1.
When displaying this on a php page, I want it to display this value as 0,000,001 rather than it's raw data of just 1.
How do I format the number to display like this? I've never had to do it before, so I'm bewildered.
Something like this should work:
SELECT INSERT(INSERT(LPAD([value], 7, '0'), 5, 0, ','), 2, 0, ',')
FROM ....
LPAD returns a string of length 7, with leading 0's. If [value] is longer than 7 it will be truncated (from the right); so '12345678' becomes '1234567'.
The two INSERT calls insert the commas.
Edit: Changed the 1's to 0's; apparently they effectively made it a "replace" rather than an "insert".
I'd suggest doing this in code though, instead of a query, if you can.
If you would rather do it in the php, something like:
$pretty = substr(number_format(10000000 + $counter), 1);
this will work as long as counter never exceeds 9,999,999.
I have a set of questions with unique IDs in a MySQL database.
Users also have a unique ID and are to answer these questions and their answers are saved in the database.
Now, I want users to get 5 non-repeating uniquely and randomly picked questions from the pool of available ones (let's say 50) based on users ID. So when a user with id 10 starts answering his questions, but stops and wants to return later to the same page, he will get the same questions as before. A user with id 11 will get a different random set of questions, but it will always be the same for him and different from all other users.
I found that random.org can generate exactly what I need with their sequence generator that generates a random sequence of numbers based on provided ID:
https://www.random.org/sequences/?min=1&max=50&col=1&format=plain&rnd=id.10
But I would like the generation to be done locally instead of relying random.org API.
So, I need to generate 'X' unique random integers, within specified range 'Y' that are generated based on supplied integer 'Z'. I should be able to call a function with 'Z' as parameter and receive back the same 'X' integers every time.
I need to know how to replicate this generation with PHP code or at least a push or hint in a direction of a PHP function, pseudo-code or code snippet that will allow me to do it myself.
Thank you in advance!
Why reinvent the wheel
mt_srand(44);
for ($i=0; $i < 10; $i++) echo mt_rand(). "\n";
echo "\n\n";
mt_srand(44);
for ($i=0; $i < 10; $i++) echo mt_rand(). "\n";
result
362278652
928876241
1914830862
68235862
1599103261
790008503
1366233414
1758526812
771614145
1520717825
362278652
928876241
1914830862
68235862
1599103261
790008503
1366233414
1758526812
771614145
1520717825
Generate your random numbers at the beginning and save it in a session. That way the random numbers for that user is always known and you can know what id of question you should go back to by looking it up in the session.
Cheers
you can get random $w array values. try this code as example and change with your logic.
$w = array('0'=>11,'1'=>22,'2'=>44,'3'=>55,'4'=>66,'5'=>88);
$str = '';
for($i=0;$i<5;$i++) {
$str.= $w[rand(0,5)];
}
As this article suggests, you could use a non-repeating pseudo random number generator. Only problem would be to generate a primnumber that is atleast 2x as big as the upper-bound for IDs and satisfies the condition p = 3 in the ring Z4. Though there should be big-enough primnumbers matching the conditions on the net for free use.
Due to my lack of experience with PHP i can only provide pseudocode though.
int[] generateUniqueRands(int id , int ct)
int[] res
const int prim//the primnumber described above
for int i in [0 , ct[
res[i] = ((id + i) * (id + i)) % prim
return res
Note that this algorithm basically works like a window:
id = x set = [a , b , c , d]
id = x + 1 set = [b , c , d , e]
...
If you wish to avoid this kind of behavior just generate a unique random-number from the id first (can be achieved in the same way the set of random numbers is generated).
When the user with ID 10 opens the page for the first time, use rand() to generate random numbers then store them into a cell in the users table in database. So the user with id 10 has the rand() numbers stored.
For example the users table has id, rand_questions.
Check if the rand_questions is empty then update with the new random numbers generated, else you get the numbers from the database.
Context and goal
In table clients I have a column clientNum CHAR(11) NOT NULL with UNIQUE KEY constraint. It contains client number in the format xxx-xxx-xxx where x is a decimal digit. For more details on the format see below.
I want to implement something like AUTO_INCREMENT for this column so that each client gets their number calculated automatically. From MySQL CREATE TABLE docs:
An integer or floating-point column can have the additional attribute AUTO_INCREMENT. When you insert a value of NULL (recommended) or 0 into an indexed AUTO_INCREMENT column, the column is set to the next sequence value. Typically this is value+1, where value is the largest value for the column currently in the table. AUTO_INCREMENT sequences begin with 1.
So I want to find the next number available and use it as clientNum value for newly inserted client row. Next number available is current maximum of clientNum incremented.
I’m coding in PHP using PDO to access the MySQL database (see PDO Tutorial for MySQL Developers).
Client number format
As stated above, the client number is in format xxx-xxx-xxx where x is a decimal digit. The range of each segment is 000 to 999. It is basically a 9-digit integer with leading zeroes and dash as thousands separator. It cannot get above 999-999-999.
Currently we want it be even more restricted, specifically in format 000-1xx-xxx (between 000-100-000 and 000-199-999). But there are already some numbers in the database that can start anywhere from 000-000-001 to 500-000-000.
Unfortunately it has to be stored in this format, I cannot change it.
Finding maximum
I need to get the max number in range 000-100-000 to 000-199-999, values outside this range must be ignored. This is where my problem comes in because as said before some numbers already exist above this.
Maximum is never 000-199-999. Otherwise in would result in adding 000-200-000 and the next time called maximum will be 000-199-999 again, resulting in attempt to insert 000-200-000 again.
How incrementation works
In PHP in can be done like this:
$clientNum = "000-100-000";
$clientNum = str_replace("-", "", $clientNum);
$clientNum++;
$clientNum = implode("-", str_split(str_pad($clientNum, 9, "0", STR_PAD_LEFT), 3));
Final $clientNum value is 000-100-001.
When the initial number is 000-120-015 then the code above produces 000-120-016. Overflow propagates to the next segment, i.e. 000-100-999 becomes 000-101-000. 999-999-999 cannot be incremented.
Idea to start with
In a loop I want to get the next number available, check if that number exists in the database, and if so, redo that loop until it finds an unused number. I know how to check if it’s in the database the first time, but I’m not sure how to do the loop.
Does anyone know a way to do this?
You may want to solve this in SQL, because otherwise you need two transactions (one for reading, one for writing) and meanwhile the number could be used by a concurrent access.
In MySQL, you can use this SQL reimplementation of your PHP code:
INSERT(INSERT(LPAD(CAST(CAST(REPLACE(clientNum, '-', '') as UNSIGNED) + 1 as CHAR), 9, '0'), 7, 0, '-'), 4, 0, '-')
This increments 000-000-999 to 000-001-000 and 999-999-999 to 100-000-000 (truncated from 100-000-0000 by LPAD()). I warned you.
E.g. to just preview what the next value is, use
SELECT INSERT(INSERT(LPAD(CAST(CAST(REPLACE(clientNum, '-', '') as UNSIGNED) + 1 as CHAR), 9, '0'), 7, 0, '-'), 4, 0, '-') FROM clients
If you want to use this when inserting a new row, it is used like this:
INSERT
INTO clients(clientNum, name)
SELECT
INSERT(INSERT(LPAD(CAST(
COALESCE(MAX(CAST(REPLACE(clientNum, '-', '') AS UNSIGNED)), 0) + 1
AS CHAR), 9, '0'), 7, 0, '-'), 4, 0, '-'),
'John Doe'
FROM clients
This works regardless of what API you use to access the database, as long as it is MySQL database. The database does the computation. However, it does not work if clients is a temporary table, which I expect it not to be. More on that below.
See also string functions, CAST(), COALESCE() and INSERT … SELECT in MySQL manual.
Later you added that the permitted values are from range 000-100-000 to 000-199-999. Other values shall be ignored for the purpose of finding maximum. A WHERE clause must be added to the SELECT part of INSERT written above.
INSERT
INTO clients(clientNum, name)
SELECT
INSERT(INSERT(LPAD(CAST(
COALESCE(MAX(CAST(REPLACE(clientNum, '-', '') AS UNSIGNED)), 0) + 1
AS CHAR), 9, '0'), 7, 0, '-'), 4, 0, '-'),
'John Doe'
FROM clients
WHERE clientNum BETWEEN '000-100-000' AND '000-199-999'
Then you stated that my solution does not work for you and proposed a supposed fix:
INSERT
INTO clients(clientNum, name)
VALUES
(SELECT
INSERT(INSERT(LPAD(CAST(
COALESCE(MAX(CAST(REPLACE(clientNum, '-', '') AS UNSIGNED)), 0) + 1
AS CHAR), 9, '0'), 7, 0, '-'), 4, 0, '-')
FROM clients AS tmptable
WHERE clientNum BETWEEN '000-100-000' AND '000-199-999'),
'John Doe'
This uses a subquery instead of the INSERT … SELECT syntax.
In MySQL, table cannot be modified (by INSERT in this case) and read by a subquery at the same time. Quoting the subquery manual:
In MySQL, you cannot modify a table and select from the same table in a subquery. This applies to statements such as DELETE, INSERT, REPLACE, UPDATE, and (because subqueries can be used in the SET clause) LOAD DATA INFILE.
However, you found a workaround using a temporary table. A temporary table is used when an alias (in this case clients AS tmptable) is defined, which evades reading from and writing to the same table at the same time. You used temporary table to store the original table, the article describing the workaround uses it to store the result of the subquery (which is more efficient, I guess). Both approaches work.
At this point I want to point out that my solution should work (and works for me!) too except for the improbable case when clients is a temporary table. I think I can expect it not to be one. Quoting the INSERT … SELECT manual page:
When selecting from and inserting into a table at the same time, MySQL creates a temporary table to hold the rows from the SELECT and then inserts those rows into the target table. However, it remains true that you cannot use INSERT INTO t ... SELECT ... FROM t when t is a TEMPORARY table, because TEMPORARY tables cannot be referred to twice in the same statement (see Section C.5.7.2, “TEMPORARY Table Problems”).
As for me this is explicitly saying that my original approach using INSERT … SELECT should work.
Just to provide a complete answer, I’ll address your original request for PHP solution using database polling. Once more I must add that this is certainly not a good solution.
Your clientNum column must be a unique key. You need to repeat the following steps until successful update:
Get the current maximum of clientNum.
Increment the obtained value.
Try to insert the row.
If successful, finish, otherwise throw the clientNum max value away and loop.
The insertion will fail due to violation of the aforementioned unique key constraint. This happens when another connection to the database successfully performs an insert in the meantime between steps 1. and 3..
You should prepare the statement outside the loop using PDO::prepare() and then execute it in the loop. The return value of execute method indicates success (true) or failure (false).
This is enough info to implement step 3.. Steps 1. and 2. consist of fetching the result of
SELECT MAX(clientNum) FROM clients
and running it through the code provided by Stephanus Yanaputra. Step 4. is a simple loop condition using the return value from execution of INSERT query in step 3..
<?php
mysql_connect(....);
mysql_select_db($db_name);
$res=mysql_query("select ClientNum from ClientTable");
$name_arr=array();
while($row=mysql_fetch_array($res))
{
foreach($row as $name)
$name_arr[]=$name;
}
$clientNum="000-000-000";
while(true){
$clientNum = str_replace("-", "", $clientNum);
$clientNum++;
if($clientNum>999999999)
{
echo("No mismatch found");
break;
}
$clientNum = implode("-", str_split($clientNum, 3));
if(!in_array($clientNum, $name_arr))
{
echo "The first unmatched clientNum is:".$clientNum;//This is what you want.
break;
}
}
?>
Comments
The query execution only once i.e. outside the while loop makes it less time complex. The time complexity is reduced due to use of array instead of execution of the query itself multiple times because searching in an array is comparatively very less time complex than searching in the database.
An easy solution based on function that you provided.
Change the function name rawr() to any naming that you like. (I couldn't find the best name and ended up using some gibberish name lol).
function rawr($in)
{
$num = str_replace("-", "", $in);
$num++;
// Convert back
$str = (string) $num;
// Add Leading 0
while(strlen($str) < 9)
{
$str = "0" . $str;
}
echo $str . "<br />";
$final = substr($str,0,3) . "-" . substr($str,3,3) . "-" . substr($str,6,3);
return $final;
}
To test it, try this code:
echo rawr(0);
echo "<br />";
echo rawr("000-000-000");
echo "<br />";
echo rawr("012-345-678");
echo "<br />";
echo rawr("123-456-789");
echo "<br />";
This will give an output that you desire. However you will have to code it yourself to test the database. In my opinion, this is not the best way to solve your problem, but it should work :)