My goal is to search column A for string B and if it is found, return which row it was found in, and if it wasn't found, I would need to know that as well in order to take a different course of action.
My current PHP code:
$string = "teststring";
$searchquery = "SELECT *
FROM AllStringsTable
WHERE `Column_A` LIKE '$string'"
$searchresult = mysql_query($searchquery) or die(mysql_error());
$row = mysql_fetch_row($searchresult);
echo "The returned row was: $row";
This just breaks and does nothing, so I think I'm way off here. Also, I have read that for exact string searching that doesn't require wildcard substrings, etc, LIKE is not needed. So I'm not sure what I would use instead...
You're almost there. You need the % wildcards:
// First, prevent sql injection with mysql_real_escape_string
$string = mysql_real_escape_string($string);
$searchquery = "SELECT * FROM AllStringsTable WHERE `Column_A` LIKE '%{$string}%'";
// ----------------------------------------------------------------^^^-------^^^
$searchresult = mysql_query($searchquery) or die(mysql_error());
if (mysql_num_rows($searchresult) == 0) {
echo "no rows found";
}
else {
// You need to loop over the result resource to get all the rows.
// Better to use mysql_fetch_array()
while ($row = mysql_fetch_array($searchresult)) {
$print_r $row;
}
If you want to do an exact match, use = instead of LIKE:
SELECT ... WHERE Column_A = '$string';
If you want to do a substring match (which I suspect is more what you want), use LIKE with the % wildcards:
SELECT ... WHERE Column_A = '%$string%';
The difference is that the first query requires that the entire Column_A matches exactly. The second query requires only that the exact word is found somewhere in the column.
Related
I'm trying to improve my MySQL query.
SELECT gamename
FROM giveaway
WHERE gamename LIKE '$query'
I got an input that consists of URL's that are formed like:
http://www.steamgifts.com/giveaway/l7Jlj/plain-sight
http://www.steamgifts.com/giveaway/okjzc/tex-murphy-martian-memorandum
http://www.steamgifts.com/giveaway/RqIqD/flyn
http://www.steamgifts.com/giveaway/FzJBC/penguins-arena-sednas-world
I take the game name from the URL and use this as input for a SQL query.
$query = "plain sight"
$query = "tex murphy martian memorandum"
$query = "flyn"
$query = "penguins arena sednas world"
Now in the database the matching name sometimes has more characters like : ' !, etc.
Example:
"Plain Sight"
"Tex Murphy: Martian Memorandum"
"Fly'N"
"Penguins Arena: Sedna's World!"
So when putting in the acquired name from the URL this doesn't produce results for the 2nd, 3rd and 4th example.
So what I did was use a % character.
$query = "plain%sight"
$query = "tex%murphy%martian%memorandum"
$query = "flyn"
$query = "penguins%arena%sednas%world"
This now gives result on the 1st and 2nd example.
.
On to my question:
My question is, how to better improve this so that also the 3rd and 4th ones work?
I'm thinking about adding extra % before and after each character:
$query = "%f%l%y%n%"
$query = "%p%e%n%g%u%i%n%s%a%r%e%n%a%s%e%d%n%a%s%w%o%r%l%d%"
But I'm not sure how that would go performance wise and if this is the best solution for it.
Is adding % a good solution?
Any other tips on how to make a good working query?
Progress:
After a bit of testing I found that adding lots of wildcards (%) is not a good idea. You will get returned unexpected results from the database, simply because you just added a lot of ways things could match.
Using the slug method seems to be the only option.
If i get your question well, you are creating a way of searching through those informations. And if that is the case then try
$query = addslashes($query);
SELECT name
FROM giveaway
WHERE gamename LIKE '%$query%'
Now if you want to enlarge your search and search for every single word that looks like the words in your string, then you can explode the text and search for each word by doing
<?php
$query = addslashes($query);
//We explode the query into a table
$tableau=explode(' ',$query);
$compter_tableau=count($tableau);
//We prepare the query
$req_search = "SELECT name FROM giveaway WHERE ";
//we add the percentage sign and the combine each query
for ($i = 0; $i < $compter_tableau; $i++)
{
$notremotchercher=$tableau["$i"];
if($i==$compter_tableau) { $liaison="AND"; } else { $liaison=""; }
if($i!=0) { $debutliaison="AND"; } else { $debutliaison=""; }
$req_search .= "$debutliaison gamename LIKE '%$notremotchercher%' $liaison ";
}
//Now you lauch your query here
$selection=mysqli_query($link, "$req_search") or die(mysqli_error($link));
?>
By so doing you would have added the % to every word in your query which will give you more result that you can choose from.
I have been using the PHP function strpos to find results containing the characters of a string from a DB:
User Types: Hel
Results: Hello, Hell, Helli, Hella
I have it basically query the entire table:
$result = mysql_query("SELECT * FROM Events");
And then ran a while statement to see which of the results contain the characters of the input:
while($row = mysql_fetch_array($result))
{
$pos = strpos($row['Title'], $q);
if ($pos === false) {
} else {
echo $row['Title'];
}
}
And to find the number of results, I was using:
$n = $n++
Inside of the while statement.
I know you can use:
$num_rows = mysql_num_rows($result);
To find the number of results if you are only selecting those values from the database, but do I have to use this while statement to find the number of results that match the strpos function? Or can I put the strpos in to the Select From query?
Any help is greatly appreciated,
Taylor
This seems highly inefficient. Why wouldn't you simply let the database do the searching for you?
$result = mysql_query("SELECT * FROM Events WHERE Title LIKE '" . addslashes($q) . "%'");
Then just loop through the results.
You could update your SQL to something like
SELECT *
FROM Events
WHERE Title LIKE '{your_string}%'
Make sure to filter for sql injection though.
You can use the LIKE statement:
SELECT * FROM Events WHERE field1 LIKE '%something%'
Where the special % characters say "Anything of any length"; so we're searching for something (or nothing), then the string, then something (or nothing.) For example, searching for %f% will match foo, off, and affirmative.
Just as general advice, I recommend that you use php's MySQLi class; it's an improved version (hence the i), and provides prepared statements, so you won't have to worry too much about SQL injections.
I'd like to create a query in MySQL that has an optional value. When the value is specified the query is filtered by that value, when the value is not all rows are returned. Here's the idea:
public function doQuery($item = 'ANY_VALUE') {
$query = "SELECT * FROM table WHERE item = ?";
db->fetchAll($query,array($item))
...
}
doQuery(); // Returns everything
doQuery($item='item1'); // Returns only rows where item = 'item1'
Is there an easy way to do this without creating two query strings depending on the value of $item?
As far as I know, no such "any" placeholder exists.
If you can use LIKE, you could do
SELECT * FROM table WHERE item LIKE '%'
if you can append a condition, you could nullify the item clause like this:
SELECT * FROM table WHERE item = ? OR 1=1
(won't work in your example though, because you are passing "item" as a parameter)
That's all the options I can see - it's probably easiest to work with two queries, removing the WHERE clause altogether in the second one.
This would probably work, but I*m not sure whether it's a good idea from a database point of view.
public function doQuery($item = 'ANY_VALUE') {
$query = "SELECT * FROM table WHERE item = ? OR 1 = ?";
db->fetchAll($query,array($item, ($item == 'ANY_VALUE' ? 1 : 0))
...
}
Better way to do this is first generate sql query from the parameter you need to bother on, and then execute.
function doQuery($params) {
$query = 'SELECT * FROM mytable ';
if (is_array($params) // or whatever your condition ) {
$query .= 'WHERE item = ' . $params[0];
}
$query .= ' ;';
// execute generated query
execute($query);
}
You cannot get distinct results without giving distinct query strings.
Using $q = "... WHERE item = '$item'" you DO create distinct query strings depending on the value of $item, so it is not that different from using
$q = "..." . ($item=='ANY_VALUE' ? something : s_th_else);.
That said I see two or three options:
use function doQuery($item = "%") { $query = "SELECT ... WHERE item LIKE '$item'"; ...}
But then callers to that function must know that they must escape a '%' or '_' character properly if they want to search for an item having this character literally (e.g. for item = "5% alcoholic solution", giving this as argument would also find "50-50 sunflower and olive oil non alcoholic solution".
use function doQuery($item = NULL) { $query = "SELECT ..."; if ($item !== NULL) $query .= " WHERE item = '$item' "; ...} (where I use NULL to allow any other string or numerical value as a valid "non-empty" argument; in case you also want to allow to search for NULL (without quotes) you must choose another "impossible" default value, e.g., [], and you must anyway use a distinct query without the single quotes which however are very important in the general case), or even:
use function doQuery($item = NULL) { if($item === NULL) $query = "SELECT ..."; else $query = "SELECT ... WHERE item = '$item' "; ...}, which is more to type but probably faster since it will avoid an additional string manipulation (concatenation of the first and second part).
I think the 2nd & 3rd options are better than the first one. You should explain why you want to avoid these better solutions.
PS: always take care of not forgetting the quotes in the SQL, and even to properly escape any special characters (quotes, ...) in arguments which can depend on user input, as to avoid SQL injections. You may be keen on finding shortest possible solutions (as I am), but neglecting such aspects is a no-no: it's not a valid solution, so it's not the shortest solution!
Is there any way to check if a column is "anything"? The reason is that i have a searchfunction that get's an ID from the URL, and then it passes it through the sql algorithm and shows the result. But if that URL "function" (?) isn't filled in, it just searches for:
...AND column=''...
and that doesn't return any results at all. I've tried using a "%", but that doesn't do anything.
Any ideas?
Here's the query:
mysql_query("SELECT * FROM filer
WHERE real_name LIKE '%$searchString%'
AND public='1' AND ikon='$tab'
OR filinfo LIKE '%$searchString%'
AND public='1'
AND ikon='$tab'
ORDER BY rank DESC, kommentarer DESC");
The problem is "ikon=''"...
and ikon like '%' would check for the column containing "anything". Note that like can also be used for comparing to literal strings with no wildcards, so, if you change that portion of SQL to use like then you could pre-set the variable to '%' and be all set.
However, as someone else mentioned below, beware of SQL injection attacks. I always strongly suggest that people use mysqli and prepared queries instead of relying on mysql_real_escape_string().
You can dynamically create your query, e.g.:
$query = "SELECT * FROM table WHERE foo='bar'";
if(isset($_GET['id'])) {
$query .= " AND column='" . mysql_real_escape_string($_GET['id']) . "'";
}
Update: Updated code to be closer to the OP's question.
Try using this:
AND ('$tab' = '' OR ikon = '$tab')
If the empty string is given then the condition will always succeed.
Alternatively, from PHP you could build two different queries depending on whether $id is empty or not.
Run your query if search string is provided by wrapping it in if-else condition:
$id = (int) $_GET['id'];
if ($id)
{
// run query
}
else
{
// echo oops
}
There is noway to check if a column is "anything"
The way to include all values into query result is exclude this field from the query.
But you can always build a query dynamically.
Just a small example:
$w=array();
if (!empty($_GET['rooms'])) $w[]="rooms='".mysql_real_escape_string($_GET['rooms'])."'";
if (!empty($_GET['space'])) $w[]="space='".mysql_real_escape_string($_GET['space'])."'";
if (!empty($_GET['max_price'])) $w[]="price < '".mysql_real_escape_string($_GET['max_price'])."'";
if (count($w)) $where="WHERE ".implode(' AND ',$w); else $where='';
$query="select * from table $where";
For your query it's very easy:
$ikon="";
if ($id) $ikon = "AND ikon='$tab'";
mysql_query("SELECT * FROM filer
WHERE (real_name LIKE '%$searchString%'
OR filinfo LIKE '%$searchString%')
AND public='1'
$ikon
ORDER BY rank DESC, kommentarer DESC");
I hope you have all your strings already escaped
I take it that you are adding the values in from variables. The variable is coming and you need to do something with it - too late to hardcode a 'OR 1 = 1' section in there. You need to understand that LIKE isn't what it sounds like (partial matching only) - it does exact matches too. There is no need for 'field = anything' as:
{field LIKE '%'} will give you everything
{field LIKE 'specific_value'} will ONLY give you that value - it is not partial matching like it sounds like it would be.
Using 'specific_value%' or '%specific_value' will start doing partial matching. Therefore LIKE should do all you need for when you have a variable incoming that may be a '%' to get everything or a specific value that you want to match exactly. This is how search filtering behaviour would usually happen I expect.
I have made the following search script but can only search one table column when querying the database:
$query = "select * from explore where site_name like '%".$searchterm."%'";
I would like to know how I can search the entire table(explore). Also, I would need to fix this line of code:
echo "$num_found. ".($row['site_name'])." <br />";
One last thing that is bugging me is when I push the submit button on a different page I always displays the message "Please enter a search term." even when I enter in something?
Thanks for any help, here is the entire script if needed:
<?php
// Set variables from form.
$searchterm = $_POST['searchterm'];
trim ($searchterm);
// Check if search term was entered.
if (!$serachterm)
{
echo "Please enter a search term.";
}
// Add slashes to search term.
if (!get_magic_quotes_gpc())
{
$searchterm = addcslashes($searchterm);
}
// Connects to database.
# $dbconn = new mysqli('localhost', 'root', 'root', 'ajax_demo');
if (mysqli_connect_errno())
{
echo "Could not connect to database. Please try again later.";
exit;
}
// Query the database.
$query = "select * from explore where site_name like '%".$searchterm."%'";
$result = $dbconn->query($query);
// Number of rows found.
$num_results = $result->num_rows;
echo "Found: ".$num_results."</p>";
// Loops through results.
for ($i=0; $i <$num_results; $i++)
{
$num_found = $i + 1;
$row = $result->fetch_assoc();
echo "$num_found. ".($row['site_name'])." <br />";
}
// Escape database.
$result->free();
$dbconn->close();
?>
Contrary to other answers, I think you want to use "OR" in your query, not "AND":
$query = "select * from explore where site_name like '%".$searchterm."%' or other_column like '%".$searchterm."%'";
Replace other_column with the name of a second column. You can keep repeating the part I added for each of your columns.
Note: this is assuming that your variable $searchterm has already been escaped for the database, for example with $mysqli->real_escape_string($searchterm);. Always ensure that is the case, or better yet use parameterised queries.
Similarly when outputting your variables like $row['site_name'] always make sure you escape them for HTML, for example using htmlspecialchars($row['site_name']).
One last thing that is bugging me is when I push the submit button on a different page I always displays the message "Please enter a search term." even when I enter in something?
Make sure that both forms use the same method (post in your example). The <form> tag should have the attribute method="post".
Also, what is wrong with the line of code you mentioned? Is there an error? It should work as far as I can tell.
A UNION query will provide results in a more optimized fashion than simply using OR. Please note that utilizing LIKE in such a manner will not allow you to utilize any indexes you may have on your table. You can use the following to provide a more optimized query at the expense of losing a few possible results:
$query = "SELECT * FROM explore WHERE site_name LIKE '".$searchterm."%'
UNION
SELECT * FROM explore WHERE other_field LIKE '".$searchterm."%'
UNION
SELECT * FROM explore WHERE third_field LIKE '".$searchterm."%'";
This query is probably as fast as you're going to get without using FULLTEXT searching. The downside, however, is that you can only match strings beginning with the searchterm.
To search other columns of table you need to add conditions to your sql
$query = "select * from explore where site_name like '%".$searchterm."%' or other_column like '%".$searchterm."%'";
But if you don't know that I would strongly advise going through some sql tutorial...
Also I didn't see anything wrong with this line
echo "$num_found. ".($row['site_name'])." <br />";
What error message are you getting?
Just add 'AND column = "condition"' to the WHERE clause of your query.
Be careful with adding lots of LIKE % conditions as these can be very slow especially if using a front wild card. This causes the RDBMS to search every row. You can optimize if you use an index on the column and only a trailing wildcard.
You are searching the whole table, just limiting the results to those where the site_name like '%".$searchterm."%'. If you want to search everything from that table, you need to remove the WHERE clause
Here's the corrected line. You had a few too many quotes in it.
echo $num_found.".".($row['site_name'])." <br />";
Regarding displaying the message, you have a typo in your code:
// Check if search term was entered.
if (!$serachterm)
should be:
// Check if search term was entered.
if (!$searchterm)
In the code you have written, !$serachterm always evaluates to true because you never declared a variable $seracherm (note the typo).
your code is very bugy for sql injection first do
do this
$searchterm = htmlspecialchars($searchterm);
trim($searchterm);
next
$query = mysql_real_escape_string($query);
finaly your search looks like this
$query = "select * from explore where site_name like '%$searchterm%';