Pass an SQL query to php PDO function and execute [duplicate] - php

Question

Currently Im trying to create a PDO class where I will have a method to run a query like INSERT, UPDATE, or DELETE.
For examaple this is my method for a SELECT
public function getPreparedQuery($sql){
$stmt = $this->dbc->prepare($sql);
$stmt->execute([5]);
$arr = $stmt->fetchAll(PDO::FETCH_ASSOC);
if(!$arr) exit('No rows');
$stmt = null;
return $arr;
}
And i Simply call it like this:
$stmt = $database->getPreparedQuery($sql2);
var_export($stmt);
And so far I know that a runQuery should work something similar to this:
Insert Example without using a method:
$idRol = "6";
$nomRol = "test6";
$stmt = $database->dbc->prepare("insert into roles (idRol, NomRol) values (?, ?)");
$stmt->execute(array($idRol,$nomRol));
$stmt = null;
But I want to make it into an universal method where i simply can pass the sql sentence, something like this:
$database->runQuery($query);
but the query can happen to be
$query = "INSERT INTO roles (idRol, NomRol) VALUES ('4','test')";
or
$query = "INSERT INTO movies (movName, movLength, movArg) VALUES ('name1','15','movie about...')";
So how do I slice the arg $query so I can get all the variables that are being used in order to make an universal runQuery?
Because I can imagine that my method should be something like this
runQuery([$var1 , $var2, $var3....(there can be more)] , [$var1value, $var2value, $var3value...(there can be more)]){
$stmt = $database->dbc->prepare("insert into movies($var1 , $var2, $var3....(there can be more)) values (?, ? , ? (those are the values and there ca be more than 3)"); //how do i get those "?" value and amount of them, and the name of the table fields [movName, movLength, movArg can be variable depending of the sentence]?
$stmt->execute(array($var1,$var2, $var3, ...)); //this is wrong , i dont know how to execute it
$stmt = null;
}

Answer 1

You need to add a second parameter to your function. Simply an array where all those variables would go. An array by definition can have an arbitrary number of elements, which solves your problem exactly:
public function runQuery($sql, $parameters = []) {
$stmt = $this->dbc->prepare($sql);
$stmt->execute($parameters);
return $stmt;
}
this simple function will run ANY query. You can see the usage example in my article dedicated to PDO helper functions:
// getting the number of rows in the table
$count = $db->runQuery("SELECT count(*) FROM users")->fetchColumn();
// the user data based on email
$user = $db->runQuery("SELECT * FROM users WHERE email=?", [$email])->fetch();
// getting many rows from the table
$data = $db->runQuery("SELECT * FROM users WHERE salary > ?", [$salary])->fetchAll();
// getting the number of affected rows from DELETE/UPDATE/INSERT
$deleted = $db->runQuery("DELETE FROM users WHERE id=?", [$id])->rowCount();
// insert
$db->runQuery("INSERT INTO users VALUES (null, ?,?,?)", [$name, $email, $password]);
// named placeholders are also welcome though I find them a bit too verbose
$db->runQuery("UPDATE users SET name=:name WHERE id=:id", ['id'=>$id, 'name'=>$name]);
// using a sophisticated fetch mode, indexing the returned array by id
$indexed = $db->runQuery("SELECT id, name FROM users")->fetchAll(PDO::FETCH_KEY_PAIR);
As you can see, now your function can be used with any query with any number of parameters