PDO using MySql Case for ordering with bound variables - php

I've been researching this and I think I've found the best solution but I'm not 100% sure. I have a good handle on PDO but this is the first time I've encountered CASE in mysql. This code is working but I'm wondering if it's efficient? If I were to have multiple keys, I would have to write many arrays to be able to search and order. Is there a shorter way to write this code or is this the most efficient? Thanks!
$filters = "
AND (name LIKE :keys
OR note LIKE :keys
OR tagnum = :skeys)
";
$order = "
ORDER BY
CASE
WHEN tagnum = :skeys THEN 0
WHEN name = :skeys THEN 1
WHEN name LIKE :lkeys THEN 2
WHEN name LIKE :rkeys THEN 3
ELSE 4
END
ASC
";
$arr[':keys'] = "%$keys%"; // both wild cards
$arr[':skeys'] = $keys; // stripped keys, no wild cards
$arr[':lkeys'] = "$keys%"; // left key, right wild card
$arr[':rkeys'] = "%$keys"; // right key, left wild card

If you want to have complete control over how you order your resultset, then your solution is perfect. However, if you have multiple keys, then I would definitely consider using fulltext search because it will be faster and lot less comlicated to code. However, it has a different ranking algorithm than you have now.

Related

MYSQL PHP check a like statement on more one column at once

I have query I have came up with for a search bar. I know I can use OR to split the statement to check different columns:
$query = mysql_query('SELECT * FROM PRODUCTS WHERE cats LIKE "%'.$s.'%" OR sub_cats LIKE "%'.$s.'%"');
But if I want to check more than 2 or three columns is the re a way doing something like this to speed things up a bit:
$query_string = explode('&&=',$_GET['q']);
$db_str = 'SELECT * FROM products WHERE name, cats, sub_cats, desc, brand ';
for($x = 0; $x < count($query_string); $x++){
$enc = mysql_real_escape_string($query_string[$x]);
if($x == (count($query_string) -1)){
$db_str .= 'LIKE "%'.$enc.'%"';
}else{
$db_str .= 'LIKE "%'.$enc.'%" ';
}
}
$query = mysql_query($db_str);
I normally used POST for search bars but I fancy giving GET a go it looks more user friendly to me.
I don't know if this would speed things up (you would have to test on your data). However, the following is an alternative with only one comparison:
WHERE concat_ws('|', name, cats, sub_cats, desc, brand) LIKE '%$enc%'
Because your like has a wildcard at the beginning, the query does not use regular indexes. So this version should not slow things down much, if at all.
The answer to your performance problem, though, may be a full text index.
Your code will not work like that, even ignoring the deprecated API. You would need to do something like this:
$searchFields = ['name', 'cats', 'sub_cats', 'desc', 'brand'];
$searchTerm = mysql_real_escape_string($query_string[$x]);
$filters = implode(' OR ', array_map(function($field) use ($searchTerm) {
return "$field LIKE '%{$searchTerm}%'";
}, $searchFields));
$query = mysql_query('SELECT * FROM products WHERE '.$filters);
It's far from optimal though, and will quickly become slow as database and userbase grow. It is however exactly how for example phpMyAdmin implements its database-wide searches. If your database is larger than a few records, or is likely to attract more than a handful of searches simultaneously, you should implement a smarter solution like full text search or implement an external search engine like Apache SOLR, Amazon CloudSearch and the like - relational databases like MySQL on their own just aren't good at messy searching nor were they ever meant to be.
As for this remark:
I normally used POST for search bars but I fancy giving GET a go it
looks more user friendly to me.
This isn't really the good argument to choose. As a rule:
GET is for repeatable requests, that the user can F5 on as much as they want.
POST is for non-repeatable requests, that are usually considered harmful if (overly) repeated.
If your name is Google and you have a gazillion servers all over the world, use GET. If you already know your search has bad performance, stick with POST and don't tempt the lions.

Having difficulties sorting data from mysql query using php

This code is used to get a specific list of ID's from one table, then use those ID's to get the information from another table. Once I get all the information from the 2nd table, I am attempting to sort the data alphabetically based on a field in the 2nd table.
Example, I am getting the name based on a correlating ID and then want to display the entire result in alphabetical order by name (artist_name).
Here is the code I have. When I execute this without the sort(), it works fine but is not in alphabetical order. When I add the sort() in the 2nd while statement, the page looks the same but the name and other data do not display. The source code in the browser shows that the results are being accounted for but the sort must be preventing the variables or information from being displayed for some reason.
I haven't used a sort function before and I tried looking at some examples but couldn't really find something specific to my situation. Any and all help would be greatly appreciated. I have already looked at the PHP manual for sort so no need to send me a link to it ;-)
<?php $counter = 0;
$artistInfo = mysql_query("SELECT DISTINCT event_url_tbl.artist_id FROM event_url_tbl WHERE (SELECT cat_id FROM artist_tbl WHERE artist_tbl.artist_id = event_url_tbl.artist_id) = 1");
while ($aID = mysql_fetch_array($artistInfo))
{
$getArtistInfo = mysql_query("SELECT * FROM artist_tbl WHERE artist_id = '" . $aID['artist_id'] . "'");
while($artist = mysql_fetch_array($getArtistInfo))
{
sort($artist);?>
<a class="navlink" href="<?=HOST?><?=$artist['page_slug']?>/index.html">
<?=$artist['artist_name']?>
</a><br />
<?php }
}
?>
Your best bet, as a commenter mentioned, is to use an ORDER BY clause in SQL.
SELECT *
FROM artist_tbl
WHERE artist_id = XXX
ORDER BY artist_name ASC
The other commenter who suggested using PDO or mysqli is also correct, but that's a different issue.
To answer your specific question about sorting, according to the manual,
Blockquote Note: This function assigns new keys to the elements in array. It will remove any existing keys that may have been assigned, rather than just reordering the keys.
This means all of your array keys ('page_slug', 'artist_name', etc) are wiped out. So when you try to refer to them later, there is no data there.
Were you to use this method, you would want to use asort to sort an associative array.
However, you don't want to use sort here. What you're sorting is the variables for one row of data (one individual artists), not all of your artists. So if you think of each artist row as an index card full of data (name, id#, page slug, etc) all you're doing is moving those items around on the card. You're not reorganizing your card catalog.
Using an order by clause in the SQL statement (and rewriting in PDO) is your best bet.
Here is how I would rewrite it. I have to take some guesses at the SQL because I'm not 100% sure of your database structure and what you're specifically trying to accomplish, but I think this would work.
$query_str = "
SELECT
artist.name,
artist.page_slug
FROM
artist_tbl AS artist
INNER JOIN event_tbl AS event
ON event.artist_id = artist.artist_id
WHERE
artist.cat_id = 1
ORDER BY
artist.name ASC";
$db_obj = new PDO (/*Connection stuff*/);
$artists_sql = $db_obj->prepare ($query_str);
$artists_sql->execute ();
while ($artist = $artists_sql->fetch (PDO::FETCH_ASSOC)) {
$return_str .= "<a class='navlink' href='{HOST}
{$artist['page_slug']}/index.html'>
{$artist['artist_name']}</a><br/>";
}
echo $return_str;
In all honesty, I would probably create an artist class with a display_link method and use PDO's fetchObject method to instantiate the artists, but that's getting ahead of ourselves here.
For now I stuck with procedural code. I don't usually like to mix my HTML and PHP so I assign everything to a return string and echo it out at the end. But this is close to what you had, using one SQL query (in PDO - seriously worth starting to use if you're creating new code) that should give you a list of artists sorted by name and their associated page_slugs.
You could do all of this in one query:
SELECT * FROM event_url_tbl AS event
INNER JOIN artist_tbl AS artist ON event.artist_id = artist.id
ORDER BY artist.name DESC;
This cuts out a lot of the complexity/foreaches in your script. You'll end up with
Label1 (Label 1 details..) Artist1 (Artist1 details..)
Label1 (Label 1 details..) Artist2 (Artist1 details..)
Label2 (Label 2 details..) Artist3 (Artist1 details..)
Always good to bear in mind "one query is better than many". Not a concrete rule, just if it's possible to do, try to do it. Each query has overheads, and queries in loops are a warning sign.
Hopefully that helps

how to implement the an effective search algorithm when using php and a mysql database?

I'm new to web design, especially backend design so I have a few questions about implementing a search function in PHP. I already set up a MySQL connection but I don't know how to access specific rows in the MySQL table. Also is the similar text function implemented correctly considering I want to return results that are nearly the same as the search term? Right now, I can only return results that are the exact same or it gives "no result." For example, if I search "tex" it would return results containing "text"? I realize that there are a lot of mistakes in my coding and logic, so please help if possible. Event is the name of the row I am trying to access.
$input = $_POST["searchevent"];
while ($events = mysql_fetch_row($Event)) {
$eventname = $events[1];
$eventid = $events[0];
$diff = similar_text($input, $event, $hold)
if ($hold == '100') {
echo $eventname;
break;
else
echo "no result";
}
Thank you.
I've noticed some of the comments mentioned more efficient ways of performing the search than with the "similar text" function, if I were to use the LIKE function, how would it be implemented?
A couple of different ways of doing this:
The faster one (performance wise) is:
select * FROM Table where keyword LIKE '%value%'
The trick in this one is the placement of the % which is a wildcard, saying either search everything that ends or begins with this value.
A more flexible but (slightly) slower one could be the REGEXP function:
Select * FROM Table WHERE keyword REGEXP 'value'
This is using the power of regular expressions, so you could get as elaborate as you wanted with it. However, leaving as above gives you a "poor man's Google" of sorts, allowing the search to be bits and pieces of overall fields.
The sticky part comes in if you're trying to search names. For example, either would find the name "smith" if you searched SMI. However, neither would find "Jon Smith" if there was a first and last name field separated. So, you'd have to do some concatenation for the search to find either Jon OR Smith OR Jon Smith OR Smith, Jon. It can really snowball from there.
Of course, if you're doing some sort of advanced search, you'll have to condition your query accordingly. So, for instance, if you wanted to search first, last, address, then your query would have to test for each:
SELECT * FROM table WHERE first LIKE '%value%' OR last LIKE '%value%' OR address LIKE '%value'
Look at below example :
$word2compare = "stupid";
$words = array(
'stupid',
'stu and pid',
'hello',
'foobar',
'stpid',
'upid',
'stuuupid',
'sstuuupiiid',
);
while(list($id, $str) = each($words)){
similar_text($str, $word2compare, $percent);
if($percent > 90) // Change percentage value to 80,70,60 and see changes
print "Comparing '$word2compare' with '$str': ";
}
You can check with $percent parameter for how strong match you want to apply.

How to filter by multiple fields in MySQL/PHP

I'm writing a filter/sorting feature for an application right now that will have text fields above each column. As the user types in each field, requests will be sent to the back-end for sorting. Since there are going to be around 6 text fields, I was wondering if there's a better way to sort instead of using if statements to check for each variable, and writing specific queries if say all fields were entered, just one, or just two fields, etc.
Seems like there would be a lot of if statements. Is there a more intuitive way of accomplishing this?
Thanks!
Any initial data manipulation, such as sorting, is usually done by the database engine.
Put an ORDER BY clause in there, unless you have a specific reason the sorting needs done in the application itself.
Edit: You now say that you want to filter the data instead. I would still do this at the database level. There is no sense in sending a huge dataset to PHP, just for PHP to have to wade through it and filter out data there. In most cases, doing this within MySQL will be far more efficient than what you can build in PHP.
Since there are going to be around 6 text fields, I was wondering if there's a better way to sort instead of using if statements to check for each variable
Definitely NO.
First, nothing wrong in using several if's in order.
Trust me - I myself being a huge fan of reducing repetitions of code, but consider these manually written blocks being the best solution.
Next, although there can be a way to wrap these condition ns some loop, most of time different conditions require different treatment.
however, in your next statements you are wrong:
and writing specific queries
you need only one query
Seems like there would be a lot of if statements.
why? no more than number of fields you have.
here goes a complete example of custom search query building code:
$w = array();
$where = '';
if (!empty($_GET['rooms'])) $w[]="rooms='".mesc($_GET['rooms'])."'";
if (!empty($_GET['space'])) $w[]="space='".mesc($_GET['space'])."'";
if (!empty($_GET['max_price'])) $w[]="price < '".mesc($_GET['max_price'])."'";
if (count($w)) $where="WHERE ".implode(' AND ',$w);
$query="select * from table $where";
the only fields filled by the user going to the query.
the ordering is going to be pretty the same way.
mesc is an abbreviation for the mysql_real_escape_string or any other applicable database-specific string escaping function
select * from Users
order by Creadted desc, Name asc, LastName desc, Status asc
And your records will be sorted by order from query.
First by Created desc, then by Name asc and so on.
But from your question I can see that you are searching for filtering results.
So to filter by multiple fileds just append your where, or if you are using any ORM you can do it through object methods.
But if its simple you can do it this way
$query = "";
foreach($_POST['grid_fields'] as $key => $value)
{
if(strlen($query) > 0)
$query .= ' and '
$query .= sprintf(" %s LIKE '%s' ", mysql_real_escape_string($key), '%' .mysql_real_escape_string($value) .'%');
}
if(strlen($query) > 0)
$original_query .= ' where ' . $query;
this could help you to achieve your result.
No. You cannot avoid the testing operations when sorting the set, as you have to compare the elements in the set in same way. The vehicle for this is an if statement.
Could you take a look at this?
WHERE (ifnull(#filter1, 1) = 1 or columnFilter1 = #filter1)
and (ifnull(#filter2, 1) = 1 or columnFilter2 = #filter2)
and (ifnull(#filter3, 1) = 1 or columnFilter3 = #filter3)
and (ifnull(#filter4, 1) = 1 or columnFilter4 = #filter4)
and (ifnull(#filter5, 1) = 1 or columnFilter5 = #filter5)
and (ifnull(#filter6, 1) = 1 or columnFilter6 = #filter6)
Please let me know if I'm misunderstanding your question.. It's not like an IF statement batch, and is pretty lengthy, but what do you think?

php code, better way of grabbing sql data

I need to grab data from two tables, but I know theres a better, more tidier way to do this. Is it some kind of JOIN i need?
I'll show you my code and you'll see what I mean:
if ($rs[firearm] != "") {
$sql_result2 = mysql_query("SELECT * FROM db_firearms WHERE name='$rs[firearm]'", $db);
$rs2 = mysql_fetch_array($sql_result2);
$sql_result3 = mysql_query("SELECT * FROM items_firearms WHERE player='$id'", $db);
$rs3 = mysql_fetch_array($sql_result3);
if ($rs3[$rs2[shortname]] < 1) {
mysql_query("UPDATE mobsters SET firearm = '' WHERE id ='$id'");
}
}
This question is clear, but your code example has alot of formatting issues and I cannot give you direct answer, based on your example code.
The reason, why your example is unclear, is because.. with what are you going to join the tables? From one table you are selecting by name='$rs[firearm]' and from another by player='$id'. You have to provide the hidden data, like $rs and also $id.
You should definitely read these about mysql join and mysql left join. But I will try to give you an example based on your code, with fixed syntax. (Keep in mind, that I'm no mysql join expert, I did not test this code and also I do not know the joining conditions.) And also, the system structure is unclear.
As I understood, this what your tables do, correct?
mobsters - Users table
items_firearms - Links from users table to items table
db_firearms - Items table
So basically, my example does this: It will have preloaded $rs value, from the users table. It will check, if there is a entry inside the links table and hook the result with them items table. However, if the links table or even the items table can return multiple entries, then this doesn't work and you need to loop your results in much more smarter way.
// I can only assume, that $id is the ID of the player
$id = 2;
// Since I dont know the $rs value, then Im going to make some up
$rs = array(
'id' => 33,
'firearm' => 'famas'
);
if ($rs['firearm']) {
$result = mysql_fetch_array(mysql_query("SELECT ifa.*, dbfa.* FROM `items_firearms` AS `ifa` LEFT JOIN `db_firearms` AS `dbfa` ON `ifa.shortname` = `dbfa.shortname` WHERE `ifa.player` = '$id'"));
if ($result['id']) {
mysql_query("UPDATE `mobsters` SET `firearm` = '' WHERE `id` = '$id'", $db);
}
}
It is pretty clear, that you are new to PHP and mysql.. So I think you should probably edit your question and talk about your higher goal. Briefly mention, what your application are you building..? What are you trying to do with the mysql queries..? Maybe provide the table structure of your mysql tables..? I'm sure, that you will get your questions votes back to normal and also we can help you much better.
NOTES
You have to quote these types of variables: $rs[firearm] -> $rs['firearm']
If you want to check if your $rs['firearm'] equals something, then there is a better way then $rs[firearm] != "". The most simple is if ($rs['firearm']) {echo 'foo';}, but will produce a notice message, when all errors reporting mode. You can use isset() and empty(), but keep in mind, that isset() checks whether the variable has been set.. Meaning, even if its false, then it has been set. empty() reacts to undefined and empty variable the same, without any messages.
Also, "" means NULL, so if you even need to use "", then use NULL instead...much neater way..
I strongly recommend to use mysql class. You can understand the basics behind that idea from this answer. This is gonna make things much more easier for you. Also, mysql class is a must-have when dealing with dynamic applications.
if ($rs3[$rs2[shortname]] < 1) { .. makes no sense.. Do you want to check if the value is empty? Then (simple): if (!$rs3[$rs2[shortname]]) { .. and a very strict standard: if (empty($rs3[$rs2[shortname]])) { ..
Also you have to quote your sql queries, see my examples above.
Is the last mysql query missing $db?

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