implement LIKE query in PDO - php

I am running problems in implementing LIKE in PDO
I have this query:
$query = "SELECT * FROM tbl WHERE address LIKE '%?%' OR address LIKE '%?%'";
$params = array($var1, $var2);
$stmt = $handle->prepare($query);
$stmt->execute($params);
I checked the $var1 and $var2 they contain both the words I want to search, my PDO is working fine since some of my queries SELECT INSERT they work, it's just that I am not familiar in LIKE here in PDO.
The result is none returned. Do my $query is syntactically correct?

You have to include the % signs in the $params, not in the query:
$query = "SELECT * FROM tbl WHERE address LIKE ? OR address LIKE ?";
$params = array("%$var1%", "%$var2%");
$stmt = $handle->prepare($query);
$stmt->execute($params);
If you'd look at the generated query in your previous code, you'd see something like SELECT * FROM tbl WHERE address LIKE '%"foo"%' OR address LIKE '%"bar"%', because the prepared statement is quoting your values inside of an already quoted string.

Simply use the following:
$query = "SELECT * FROM tbl WHERE address LIKE CONCAT('%', :var1, '%')
OR address LIKE CONCAT('%', :var2, '%')";
$ar_val = array(':var1'=>$var1, ':var2'=>$var2);
if($sqlprep->execute($ar_val)) { ... }

No, you don't need to quote prepare placeholders. Also, include the % marks inside of your variables.
LIKE ?
And in the variable: %string%

$query = "SELECT * FROM tbl WHERE address LIKE ? OR address LIKE ?";
$params = array("%$var1%", "%$var2%");
$stmt = $handle->prepare($query);
$stmt->execute($params);

You can see below example
$title = 'PHP%';
$author = 'Bobi%';
// query
$sql = "SELECT * FROM books WHERE title like ? AND author like ? ";
$q = $conn->prepare($sql);
$q->execute(array($title,$author));
Hope it will work.

Related

OR operator on single column PDO

I'm shifting my database connections from mysqli to PDO.
While updating,I'm stuck on one query:
In mysql its:
$quec='designation=10 OR designation=11 OR designation=12';
$query="select firstname,mobile,email from mt where location=".$value." and cp!=".$cpa" and (".$quec.") and dept=".$usersubdept." and mstatus=1";
Its working fine in mysqli.
In PDO i wrote:
$query="select firstname,mobile,email from mt where location=:value AND cp!=:cpa AND (:quec) AND dept=:usersubdept AND mstatus=:mstatus";
Binding the values with variables using bind syntax, I'm not getting any result row.
How to rectify the problem?
I don't think you can use :quec as a parameter, since it is actually 3 things and not a value that can be bound. Otherwise, you may have something wrong with how you're binding, perhaps, but we haven't seen your code for that. Try this:
$query="SELECT firstname, mobile, email FROM mt WHERE location = :value AND
cp != :cpa AND (" . $quec . ") AND dept = :dept AND mstatus = 1";
$stmt = $db->prepare($query);
$stmt->bindValue(':value',$value);
$stmt->bindValue(':cpa',$cpa);
$stmt->bindValue(':dept',$usersubdept);
$stmt->execute();
You need to prepare a string like this: ':id0, :id1, :id2, you can do this like this:
$designationlist = ':id'.implode(',:id', array_keys($designationIds));
then your SQL will be:
$query="select firstname,mobile,email from mt where location=:value AND cp!=:cpa AND designation IN(".$designationlist.") AND dept=:usersubdept AND mstatus=:mstatus";
and:
$parms = array_combine(explode(",", $designationlist), $designationIds);
$stmt = $PDO->prepare($query);
$res = $stmt->execute($parms);

SQL parameterized query with LIKE '% ? %' PHP

I have a Search function in php and have created it using a parameterized query to make it secure.
$words = $_POST['words']//words is the form that has the words submitted by the user
$array = explode(',', $words);
$con = mysqli_connect("localhost","user","pass","database");
$stmt = $con->prepare(" SELECT column_name FROM table WHERE column_name LIKE ?")
foreach($array as $key) { //searches each word and displays results
$stmt->bind_param('s', $key)
$stmt->execute();
$result = $stmt->get-result();
while($row = $result->fetch_assoc(){
echo $row["column_name"]
}
}
however I want $stmt statement to be
$stmt = $con->prepare(" SELECT column_name FROM table WHERE column_name LIKE '%?%' ")
otherwise people have to type in the entire value of column_name to find it.
You can use CONCAT(), like this:
LIKE CONCAT ('%', ?, '%')
You can do this as follows:
$key="%$key%"
Then bind $key.
Also see PHP Binding a Wildcard for pretty much the same question....

Convert sql to mysqli_prepare with variable variables

I'm having trouble to convert my code from sql to mysqli. $XX can be 1 or 0. When $XX=1 I want to search for it. When $XX=0, there must be no search for $XX. Same for $YY.
Old code
$sql = "SELECT name FROM tabel WHERE 1=1";
if (!empty($XX)) {$sql .= " AND XX = 1 ";}
if (!empty($YY)) {$sql .= " AND YY = 1 ";}
When $XX=1 and $YY=1, the code will look like:
$sql = "SELECT name FROM tabel WHERE 1=1 AND XX = 1 AND YY = 1";
When $XX=0 and $YY=1, the code will look like:
$sql = "SELECT name FROM tabel WHERE 1=1 AND YY = 1";
When $XX=0 and $YY=0, the code will look like:
$sql = "SELECT name FROM tabel WHERE 1=1";
The 'problem' is that I do not want to search for XX=0 because that excludes all XX=1 answers. When XX=0, it should not search for XX.
New code
$stmt = mysqli_prepare($link, "SELECT name FROM tabel WHERE XX=? and YY=?");
mysqli_stmt_bind_param($stmt, "ii", $XX, $YY);
Who knows how the mysqli code must look like? Thanks!
EDIT
Okay, from what I get now, it should be simple. If the only possible value for XX and YY in the query is 1, you don't need bind_param.
$qry = 'SELECT name FROM table WHERE 1=1';
$qry .= (!empty($XX)) ? ' AND XX=1';
$qry .= (!empty($YY)) ? ' AND YY=1';
$stmt = mysqli_prepare($link, $qry);
And then just execute your query.
You can rewrite the query in the following way
SELECT * FROM table1 WHERE (xx = ? OR ? = 0) AND (yy = ? OR ? = 0)
Here is SQLFiddle demo
$sql = "SELECT * FROM table1 WHERE (xx = ? OR ? = 0) AND (yy = ? OR ? = 0)";
$db = new mysqli(...);
$stmt = $db->prepare($sql)) {
$stmt->bind_param('iiii', $xx, $xx, $yy, $yy);
$stmt->execute();
$stmt->bind_result(...);
another alternate if you can pass the field name as parameter
$stmt = mysqli_prepare($link, "SELECT name FROM tabel WHERE XX=? and YY=?");
mysqli_stmt_bind_param($stmt, "ii", $XX, $YY);
if you want to avoid filtering XX pass $XX as 'XX'(i.e field name) insted of 0
In such a special case when no variable is actually going into query, you can stick to your current setup. Just change prepare and bind to mysqli_query().
However, in case you need to add a variable into query, you either can use peterm's dirty solution or create the conditional query with placeholders and then call bind_param() with variable number of parameters using call_user_func_array()

Possible to have PHP MYSQL query ignore empty variable in WHERE clause?

Not sure how I can do this. Basically I have variables that are populated with a combobox and then passed on to form the filters for a MQSQL query via the where clause. What I need to do is allow the combo box to be left empty by the user and then have that variable ignored in the where clause. Is this possible?
i.e., from this code. Assume that the combobox that populates $value1 is left empty, is there any way to have this ignored and only the 2nd filter applied.
$query = "SELECT * FROM moth_sightings WHERE user_id = '$username' AND location = '$value1' AND english_name = $value2 ";
$result = mysql_query($query) or die(mysql_error());
$r = mysql_numrows($result);
Thanks for any help.
C
Use
$where = "WHERE user_id = '$username'";
if(!empty($value1)){
$where .= "and location = '$value1'";
}
if(!empty($value2 )){
$where .= "and english_name= '$value2 '";
}
$query = "SELECT * FROM moth_sightings $where";
$result = mysql_query($query) or die(mysql_error());
$r = mysql_numrows($result);
Several other answers mention the risk of SQL injection, and a couple explicitly mention using prepared statements, but none of them explicitly show how you might do that, which might be a big ask for a beginner.
My current preferred method of solving this problem uses a MySQL "IF" statement to check whether the parameter in question is null/empty/0 (depending on type). If it is empty, then it compares the field value against itself ( WHERE field1=field1 always returns true). If the parameter is not empty/null/zero, the field value is compared against the parameter.
So here's an example using MySQLi prepared statements (assuming $mysqli is an already-instantiated mysqli object):
$sql = "SELECT *
FROM moth_sightings
WHERE user_id = ?
AND location = IF(? = '', location, ?)
AND english_name = ?";
$stmt = $mysqli->prepare($sql);
$stmt->bind_param('ssss', $username, $value1, $value1, $value2);
$stmt->execute();
(I'm assuming that $value2 is a string based on the field name, despite the lack of quotes in OP's example SQL.)
There is no way in MySQLi to bind the same parameter to multiple placeholders within the statement, so we have to explicitly bind $value1 twice. The advantage that MySQLi has in this case is the explicit typing of the parameter - if we pass in $value1 as a string, we know that we need to compare it against the empty string ''. If $value1 were an integer value, we could explicitly declare that like so:
$stmt->bind_param('siis', $username, $value1, $value1, $value2);
and compare it against 0 instead.
Here is a PDO example using named parameters, because I think they result in much more readable code with less counting:
$sql = "SELECT *
FROM moth_sightings
WHERE user_id = :user_id
AND location = IF(:location_id = '', location, :location_id)
AND english_name = :name";
$stmt = $pdo->prepare($sql);
$params = [
':user_id' => $username,
':location_id' => $value1,
':name' => $value2
];
$stmt->execute($params);
Note that with PDO named parameters, we can refer to :location_id multiple times in the query while only having to bind it once.
if ( isset($value1) )
$query = "SELECT * FROM moth_sightings WHERE user_id = '$username' AND location = '$value1' AND english_name = $value2 ";
else
$query = "SELECT * FROM moth_sightings WHERE user_id = '$username' AND english_name = $value2 ";
But, you can also make a function to return the query based on the inputs you have.
And also don't forget to escape your $values before generating the query.
1.) don't use the simply mysql php extension, use either the advanced mysqli extension or the much safer PDO / MDB2 wrappers.
2.) don't specify the full statement like that (apart from that you dont even encode and escape the values given...). Instead use something like this:
sprintf("SELECT * FROM moth_sightings WHERE 1=1 AND %s", ...);
Then fill that raw query using an array holding all values you actually get from your form:
$clause=array(
'user_id="'.$username.'"',
'location="'.$value1.'"',
'english_name="'.$value2.'"'
);
You can manipulate this array in any way, for example testing for empty values or whatever. Now just implode the array to complete the raw question from above:
sprintf("SELECT * FROM moth_sightings WHERE 1=1 AND %s",
implode(' AND ', $clause) );
Big advantage: even if the clause array is completely empty the query syntax is valid.
First, please read about SQL Injections.
Second, $r = mysql_numrows($result) should be $r = mysql_num_rows($result);
You can use IF in MySQL, something like this:
SELECT * FROM moth_sightings WHERE user_id = '$username' AND IF('$value1'!='',location = '$value1',1) AND IF('$value2'!='',english_name = '$value2',1); -- BUT PLEASE READ ABOUT SQL Injections. Your code is not safe.
Sure,
$sql = "";
if(!empty($value1))
$sql = "AND location = '{$value1}' ";
if(!empty($value2))
$sql .= "AND english_name = '{$value2}'";
$query = "SELECT * FROM moth_sightings WHERE user_id = '$username' {$sql} ";
$result = mysql_query($query) or die(mysql_error());
$r = mysql_numrows($result);
Be aware of sql injection and deprecation of mysql_*, use mysqli or PDO instead
I thought of two other ways to solve this:
SELECT * FROM moth_sightings
WHERE
user_id = '$username'
AND location = '%$value1%'
AND english_name = $value2 ";
This will return results only for this user_id, where the location field contains $value1. If $value1 is empty, this will still return all rows for this user_id, blank or not.
OR
SELECT * FROM moth_sightings
WHERE
user_id = '$username'
AND (location = '$value1' OR location IS NULL OR location = '')
AND english_name = $value2 ";
This will give you all rows for this user_id that have $value1 for location or have blank values.

How to bind in PDO a string with %

I have the following query, (which don't work).
How do I bid strings inside an existing string with % (I believe the % is not the problem, but really not sure).
$sql="SELECT * FROM T WHERE f LIKE '%:bindParamString%'";
You can include % symbols into your value:
$param = '%'.$param.'%';
$query = "SELECT * FROM T WHERE f LIKE ?";
Or use SQL to concatenate string in database:
## if you have mysql
$query = "SELECT * FROM T WHERE f LIKE CONCAT('%', ?, '%')";
It also a good idea to use LIKE instead of = then you're searching by patterns.
Try something like this:
$db = new PDO(...);
$sql = "SELECT * FROM T WHERE f=?";
$stmt = $db->prepare($sql);
$val = "%{$val}%";
$stmt->bindParam(1, $val, PDO::PARAM_STR);
For more info, I suggest to read the related doc page!

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