Adding data to php variable with PDO fetchAll::fetch_assoc

问题

Ok this might get confusing cos I have not totally worked out how to explain this perfectly but i'll just show code to explain better than i could in words.

Basic idea: I am trying to collect all relevant data from queries assign it to a PHP variable then return it via json.encode for use on the site where ever needs be in Javascript.

So this is an example of what i am trying to do:

$stmt = $pdo->prepare("SELECT * FROM users WHERE uid= ?");
try {
    $stmt->execute(array($uid));
} catch (PDOException $e) {
    echo $e -> getMessage();  exit;
}

if(!$stmt->rowcount()){
    return false; exit;
}

$data = $stmt->fetchAll(PDO::FETCH_ASSOC);

So i display $data at this point and i get this result:

Array ( 
  [0] => Array (
            [uid] => 1 
            [pass] => *****
            [show_name] => Dave
            [email] => test@test.com
  ) )

This is what i expected to occur :)

Next i want to add more results from queries to "$data". Like so:

    $stmt = $pdo->prepare("SELECT * FROM databank WHERE uid=?");
    try{
        $stmt->execute(array($uid));
    } catch (PDOException $e){
        echo $e -> getMessage();  exit;
    }   
$data .= $stmt->fetchAll(PDO::FETCH_ASSOC);

This is where it goes wrong... when i echo/print_r $data at this point the result is:

 ArrayArray

Can some one explain why this occurs ? And how i solve it please :)

Thank you for your time!

回答1:

You're concatenating each result to $data as though the results were strings, but they're arrays; when forced to represent an array as a string, PHP produces 'Array', which is not what you want.

Before your first line, do

 $data = array();

and in place of your last line, do

 $data[] = $stmt->fetchAll(PDO::FETCH_ASSOC)

and you should get

Array ( 
  [0] => Array (
            [uid] => 1 
            [pass] => *****
            [show_name] => Dave
            [email] => test@test.com
  ),
  [1] => Array (
            [uid] => 2
            [pass] => *****
            [show_name] => Joe
            [email] => test@test.com
  ),
  [...]
)

in $data.

Hope this helps!

来源：https://stackoverflow.com/questions/12684417/adding-data-to-php-variable-with-pdo-fetchallfetch-assoc

标签

php

sql

pdo