以JSON格式存储多个记录时出错

Question

I've problem with my code, the reason, when run query un PHP FILE, this retrieve all records from SELECT * FROM material, then it pass to JS FILE for process and store all records in an array json format, but display this error:

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result 
resource in C:\AppServ\www\biblioteca\include\doLogin.php on line 31 []

_

PHP FILE WITH FUNCTIONS

.........
public function searchMat($tipoBusqueda,$terminoBuscar){

$query = " SELECT * FROM material ";
$result = mysql_query($query) or die (mysql_error());
$resultArray =  mysql_fetch_assoc($result);
return $resultArray;
}

OTHER PHP FILE with functions

$results = $db->searchMat($tipoBusqueda, $terminoBuscar);
$jsonSearchResults = array();

if ($results != false) {
    while($row = mysql_fetch_assoc($results)) {
        $jsonSearchResults = array (
        'clavemat' => $row['cve_mat'],
        'tipomat' => $row['tipo_mat'],
        'titulomat' => $row['titulo_mat'],
        'autormat' => $row['autor_mat'],
        'editmat' => $row['edit_mat'],
        'success' => 'success', 
        );  
    }

    echo json_encode($jsonSearchResults);
} 

EDIT:

Answer 1

You're calling mysql_fetch_assoc two times. The first time on the resource you got from mysql_query, the second time on an array - invalid.

Also, when you would loop over all rows, you need to add to $jsonSearchResults. As @RezaSanaie already said, it gets overwritten each iteration in your code. It should be:

public function searchMat() {
/* returns the material table as a resource */
    $query = "SELECT * FROM material";
    $result = mysql_query($query) or die (mysql_error());
    return $result;
}

$results = $db->searchMat();
$jsonSearchResults = array();
while ($results!=false && $row = mysql_fetch_assoc($results)) {
    array_push($jsonSearchResults, array(
        'clavemat' => $row['cve_mat'],
        'tipomat' => $row['tipo_mat'],
        'titulomat' => $row['titulo_mat'],
        'autormat' => $row['autor_mat'],
        'editmat' => $row['edit_mat'],
        'success' => 'success'
    ));
}   
echo json_encode($jsonSearchResults);