So, I have this query:
FROM test.cliente, test.contratto
WHERE test.contratto.Codice_Cliente = test.cliente.Codice_Cliente
AND test.cliente.Denominazione = :name;
But I'm trying to work with something like this:
FROM test.cliente, test.contratto
WHERE test.contratto.Codice_Cliente = test.cliente.Codice_Cliente<
AND test.cliente.Denominazione LIKE "%:name%";
The reason I want to use this query is because the user puts a name into the html form, but I don't want him to type the same piece of data that I have on the database, because there's no way that what he'll type will be the same piece of data as it's written in the database.
The code goes on like this:
$name = $_POST['Denominazione'];
$statement = $connection->prepare($sql);
$statement->bindParam(':name', $name, PDO::PARAM_STR);
$statement->execute();
$result = $statement->fetchAll();
I also tried to type
$name = '%'.$_POST['Codice_Cliente'].'%';
but it didn't find me anything.
PDO prepared statements DO NOT allow % in SQL statements.
You have to use "FROM test.cliente, test.contratto
WHERE test.contratto.Codice_Cliente = test.cliente.Codice_Cliente
AND test.cliente.Denominazione LIKE :name";
And put the "%name%" inside the execute.
Please also see:
How do I create a PDO parameterized query with a LIKE statement?
PHP - Using PDO with IN clause array
Related
Sorry if this seems a really stupid question, but I'm struggling to get to grips with changing from Mysql to Mysqli and prepared statements.
So in mysql, I would have done this:
$q=('SELECT * FROM table WHERE field="'.$variable.'"');
$result = mysql_query($q);
I now know this is not good. So I now have the below:
$stmt = $mysqli->prepare('SELECT * FROM table WHERE field=? LIMIT 1');
$stmt->bind_param('s', $variable);
$stmt->execute();
Problem is that the query doesn't work. Say the ? is actually "tree". So the query becomes:
'SELECT * FROM table WHERE field=tree LIMIT 1'
If I tried to run that query in say phpmyadmin I get "Unknown column tree in where clause". Obviously if I put quotes around it then it works, hence the original query. So how can I get this to work if I can't use quotes, since then you are looking for the literal question mark?
For reference I am then using this code:
$meta = $stmt->result_metadata();
while ($field = $meta->fetch_field()) {
$parameters[] = &$row[$field->name];
}
call_user_func_array(array($stmt, 'bind_result'), $parameters);
while ($stmt->fetch()) {
foreach($row as $key => $val) {
$x[$key] = $val;
}
$results[] = $x;
}
As I can't use get_result() which is very annoying. I have PHP version 5.4, and even the mysqlnd driver, but can't enable it as I'm on a VPS and my host says it might affect other sites on that server. Consequently what is actually just two lines in MySql is actually now something like 15 lines in the 'improved' mysqli. Great.
Any help would be appreciated!
This:
$stmt = $mysqli->prepare('SELECT * FROM table WHERE field=? LIMIT 1');
$stmt->bind_param('s', $variable);
is not equivalent to this:
SELECT * FROM table WHERE field=tree LIMIT 1
Prepared statement placeholders are not the same as copy and pasting in values. You are binding the value "tree" as a string here, the database will actually understand this. The ? is not simply being replaced by the bound value, the database understands the difference between your query structure with its placeholders and the values you're binding into them. Binding the parameter this way is equivalent to running:
SELECT * FROM table WHERE field='tree' LIMIT 1
Consequently what is actually just two lines in MySql is actually now something like 15 lines in the 'improved' mysqli. Great.
Mysqli is not intended to be used as is. It is but a building material for the higher level library. When used wisely, it can give you data in one line:
$data = $db->getAll('SELECT * FROM table WHERE field=?s', $variable);
(BTW, the same goes for the old mysql ext as well)
I am using PDO to connect with my MySQL db
So before in my users list i did:
Build the query by conditions (online? new user? sex?)
prepared the query
bound the values to the query
execute
fetch in a while() to show the results
Now I am just calling a object, UserCollection, load it and foreach the output.
$list = new UserCollection( $connect );
$list->load();
like that. In load() is the standard query for now:
$stmt = $this->_pdo->query( 'SELECT id FROM users' );
$data = $stmt->fetchAll( PDO::FETCH_ASSOC );
Theres no bounded variables to it, so it is not prepared.
Works fine, and it grabs just all the users.
Now what I wish to do is pass the query, that has been build to UserCollection() and use it to load() in the query.
I could do this easy, if the query was not bounded to variables, like the query above.
So what should I do if i want to pass a variable like this:
SELECT firstname, lastname, id, sex, last_access, bostadsort FROM users WHERE sex=:sex
Then i would need to bind :sex, and i cant just write bindValue() as
the value is not inside the UserCollection object
sometimes it could be only WHERE firstname=:firstname and not :sex, so it would throw error that I have bound a value that I dont use..
So what should I do here? what can i do?
Thanks in forward
You could modify your load method:
function load($params = array()){
$stmt = $this->_pdo->prepare("*your sql here*");
if (!empty($params)){
foreach ($params as $param_key=>$param_value)
$stmt ->bindParam($param_key, $param_value);
}
$data = $stmt->fetchAll( PDO::FETCH_ASSOC );
}
this way you don't have to modify existing code. To use it with new queries with arbitrarry number of parameters you'll just call it like:
$sex = 'male';
$firstname = 'Richard';
$params = array(':sex'=>&$sex, ':firstname'=>&$firstname);
$list->load($parameters);
Don't have PHP at hand, so can't test it, but I think that should work.
I have an issue, I'm looping threw a set of values and then creating a PDO mySql query with every loop, now the problem is the first query is executing and returning results, but the second upwards aren't returning results. If I manually execute the queries on the server they return results. This is weird, maybe I'm doing something wrong here. My code below
if($num_results > 0){
for($i=0;$i<$num_results;$i++){
$sql_sub = "SELECT * FROM menu_config WHERE client_id =".$client_id ." AND id =".$data[$i]['root_menu_id'];
$results_s = $pdo->query($sql_sub);
$data_s = $results_s->fetchAll(PDO::FETCH_ASSOC);
$sub_menu_title = "<strong>".$data[$i]['title']."</strong>";
if(empty($data_s[0]['title'])){
$main_menu_title = '<span style="color:#FF0000;font-weight:bold;">No Main Menu Assigned to Sub Menu</span>';
}else{
$main_menu_title = $data_s[0]['title'];
}
$men_title = $data[$i]['title']
}
}
(this may be a little more than you asked for)
You seem to be missing out on some good things that prepared statements do.
First off, you don't usually want to pass the values directly into the query. (sometime's it's necessary, but not here). By doing that, you take out all the good stuff that protects from sql injection. Instead you want to send them as parameters after you've prepared the query.
Secondly, when in a loop, you can save yourself time and resources if you're running the same query over and over by preparing the statement, and then only changing the values you send to to that prepared statement using the PDOStatement::bindParam() function.
Thirdly, fetchAll() does not take a 'fetch_style' of PDO::FETCH_ASSOC. fetch() does. But I think you can get by with the default or none using fetchAll. You'll have to check into that and see what you need. Here are the fetchAll docs
$sql_sub = "SELECT * FROM menu_config WHERE client_id = :client_id AND id = :id ";
$query = $pdo->prepare($sql_sub);
for($i=0;$i<$num_results;$i++){
$query->bindParam(':client_id', $client_id);
$query->bindParam(':id', $data[$i]['root_menu_id']);
$query->execute();
$data_s = $query->fetchAll();
$sub_menu_title = "<strong>".$data[$i]['title']."</strong>";
if(empty($data_s[0]['title'])){
$main_menu_title = '<span style="color:#FF0000;font-weight:bold;">
No Main Menu Assigned to Sub Menu</span>';
}else{
$main_menu_title = $data_s[0]['title'];
}
$men_title = $data[$i]['title'];
}
I created this code:
$statement = $db->prepare("SELECT * FROM phptech_contact");
$statement->execute();
$result = $statement->result_metadata();
$object = $result->fetch_object();
print_r( $object );
When I run it, it doesn't work. Can anybody tell me why it doesn't work?
I have 20 rows in this table so data should be returned.
From http://ch.php.net/manual/en/mysqli-stmt.result-metadata.php
Note: The result set returned by mysqli_stmt_result_metadata() contains only metadata. It does not contain any row results. The rows are obtained by using the statement handle with mysqli_stmt_fetch().
As long as you don't need this meta data you don't need to call this method.
$statement = $db->prepare("SELECT fld1, fld2 FROM phptech_contact");
$statement->execute();
$stmt->bind_result($fld1, $fld2);
while ($stmt->fetch()) {
echo "$fld1 and $fld2<br />";
}
But I really dislike the mysqli extension. PDO is much cooler ... ;-)
$db = new PDO('...');
$stmt = $db->prepare("SELECT fld1, fld2 FROM phptech_contact");
$stmt->execute();
while ($obj = $stmt->fetchObject()) {
// ...
}
or
$objs = stmt->fetchAll(PDO::FETCH_OBJ);
if you're trying to get the rows from the database, the function you need is mysqli_stmt::fetch(), not mysqli_stmt::fetch_metadata()
You're also missing a few steps. When using prepared statements, you must specify the fields you would like to return instead of using the star wildcard, and then use mysqli_stmt::bind_result() to specify which variables the database fields should be placed in.
If you're more familiar with the original MySQL extension, prepared statements have a different process to use. If your select statement has a parameter (eg., "WHERE value=?") prepared statements are definitely recommended, but for your simple query, mysqli:query() would be sufficient, and not very different from the process of mysql_query()
I believe the problem is that mysqli_stmt::result_metadata() returns a mysqli_result object without any of the actual results — it only holds metadata.
So what you want to do is use $result = $statement->bind_result(...) and then call $result->fetch() repeatedly to get the results.
One of the comments under the bind-result() article shows how to do this for a query like yours, where you don't necessarily know all of the columns being returned.
I'm using PHP with MySQLi, and I'm in a situation where I have queries like
SELECT $fields FROM $table WHERE $this=$that AND $this2=$that2
So far I've written some code that splices up an array that I give it, for example:
$search = array(name=michael, age=20) //turns into
SELECT $fields FROM $table WHERE name=michael AND age=20
Is there a more efficient way to do this?
I'm rather worried about MySQL injections - this seems very vulnerable.
Thanks!
Oddly enough, the title to your question is basically the answer to it. You want to do something like this, using mysqli parameterized queries:
$db = new mysqli(<database connection info here>);
$name = "michael";
$age = 20;
$stmt = $db->prepare("SELECT $fields FROm $table WHERE name = ? AND age = ?");
$stmt->bind_param("si", $name, $age);
$stmt->execute();
$stmt->close();
More information in the mysqli section of the manual, specifically the functions related to MySQLi_STMT.
Note that I personally prefer using PDO over mysqli, I don't like all the bind_param / bind_result stuff that mysqli does. If I have to use it I write a wrapper around it to make it work more like PDO.