PDO：绑定问题，所有查询返回false

Question

I cannot for the life of me get binding to work with PDO queries, they always return false.

On this example, it checks that the value of a field is between 2 other values.

This works:

$query = $db->query("SELECT * FROM table WHERE field1 > '$start' AND field1 < '$finish'");

This doesn't:

$query = $db->query("SELECT * FROM table WHERE field1 > :start AND field1 < :finish");
$query->bindParam(":start", $start);
$query->bindParam(":finish", $finish);

UPDATE: The above query now works thanks to the help. The following still doesn't.

I have been trawling through various PDO posts on here but I have not found a solution, and I don't know what else to try.

UPDATE2: Okay, it seems it is not finding $db and therefore not connecting and returning false. The $db connection line is in a connect.php file that is required on all main pages. The content on those pages is called by a function that then includes the relevant file/page. Because PDO does not work by itself in functions, is it losing the $db through the function to include the file containing the query? I may not have explained myself clearly enough.

Basically, example function in functions.php:

function getRegistration() {
    include("registration.php");
}

main.php

require_once("connect.php");
require_once("functions.php");

getRegistration();

registration.php contains:

$sql = $db->prepare("INSERT INTO tempus_members(username, email, password, activation_code, registration_date, registered_ip, name) VALUES(:username, :email, :password, :activation_code, :registration_date, :registered_ip, :name)");
$sql->bindParam(":username", $username);
$sql->bindParam(":email", $email);
$sql->bindParam(":password", $hash);
$sql->bindParam(":activation_code", $activation_code);
$sql->bindParam(":registration_date", $registration_date);
$sql->bindParam(":registered_ip", $registered_ip);
$sql->bindParam(":name", $name);
$sql->execute();

Is it losing the $db variable through the function to include the page? If so, how do I carry $db through all functions?

Answer 1

Try:

$stmt = $db->prepare("SELECT * FROM table WHERE field1 > :start AND field1 < :finish");
$stmt->bindParam(":start", $start);
$stmt->bindParam(":finish", $finish);
$stmt->execute();

You were using PDO::query instead of PDO::prepare .

As for the other query, what errors are you getting back? Try the following code and see if any errors are spit out onto the page:

$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

try{
    $sql = $db->prepare("INSERT INTO tempus_members(username, email, password, activation_code, registration_date, registered_ip, name) VALUES(:username, :email, :password, :activation_code, :registration_date, :registered_ip, :name)");

    $sql->bindParam(":username", $username);
    $sql->bindParam(":email", $email);
    $sql->bindParam(":password", $hash);
    $sql->bindParam(":activation_code", $activation_code);
    $sql->bindParam(":registration_date", $registration_date);
    $sql->bindParam(":registered_ip", $registered_ip);
    $sql->bindParam(":name", $name);

    $sql->execute();

}
catch(PDOException $e){
    echo $e->getMessage();
}