Unable to concatenate sql in pdo statement [duplicate] - php

Question

This question already has answers here:
How to include a PHP variable inside a MySQL statement
(5 answers)
Closed 2 years ago.
I currently have a Get varible
$name = $_GET['user'];
and I am trying to add it to my sql statement like so:
$sql = "SELECT * FROM uc_users WHERE user_name = ". $name;
and run
$result = $pdo -> query($sql);
I get an invalid column name. But that doesn't make sense because if I manually put the request like so
$sql = "SELECT * FROM uc_users WHERE user_name = 'jeff'";
I get the column data, just not when I enter it as a get variable. What am I doing wrong. I am relatively new to pdo.
Update:
Now I have the following:
$name = $_GET['user'];
and
$sql = "SELECT * FROM uc_users WHERE user_name = :name";
//run the query and save the data to the $bio variable
$result = $pdo -> query($sql);
$result->bindParam( ":name", $name, PDO::PARAM_STR );
$result->execute();
but I am getting
> SQLSTATE[42000]: Syntax error or access violation: 1064 You have an
> error in your SQL syntax; check the manual that corresponds to your
> MySQL server version for the right syntax to use near ':name' at line
> 1

Answer 1

For your query with the variable to work like the one without the variable, you need to put quotes around the variable, so change your query to this:
$sql = "SELECT * FROM uc_users WHERE user_name = '$name'";
However, this is vulnerable to SQL injection, so what you really want is to use a placeholder, like this:
$sql = "SELECT * FROM uc_users WHERE user_name = :name";
And then prepare it as you have:
$result = $pdo->prepare( $sql );
Next, bind the parameter:
$result->bindParam( ":name", $name, PDO::PARAM_STR );
And lastly, execute it:
$result->execute();

Answer 2

I find this best for my taste while preventing SQL injection:
Edit: As pointed out by #YourCommonSense you should use a safe connection as per these guidelines
// $conn = mysqli_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
$sql = 'SELECT * FROM uc_users WHERE user_name = ?';
$stmt = $conn->prepare($sql);
$stmt->bind_param('s', $name);
$stmt->execute();
$result = $stmt->get_result();
$stmt->close();
// perhaps you'll need these as well
$count = $result->num_rows;
$row = $result->fetch_assoc();
/* you can also use it for multiple rows results like this
while ($row = $result->fetch_assoc()) {
// code here...
} */
BTW, if you had more parameters e.g.
$sql = 'SELECT * FROM table WHERE id_user = ? AND date = ? AND location = ?'
where first ? is integer and second ? and third ? are string/date/... you would bind them with
$stmt->bind_param('iss', $id_user, $date, $location);
/*
* i - corresponding variable has type integer
* d - corresponding variable has type double
* s - corresponding variable has type string
* b - corresponding variable is a blob and will be sent in packets
*/
Source: php.net
EDIT:
Beware! You cannot concatenate $variables inside bind_param
Instead you concatenate before:
$full_name = $family_name . ' ' . $given_name;
$stmt->bind_param('s', $full_name);

Answer 3

Try this .You didn't put sigle quote against variable.
$sql = "SELECT * FROM uc_users WHERE user_name = '". $name."'";
Note: Try to use Binding method.This is not valid way of fetching data.

Answer 4

$sql = "SELECT * FROM 'uc_users' WHERE user_name = '". $name."' ";