PHPs mysqli prepare - generate dynamically

问题

My code to generate the SQL statement works fine - however I run into a hiccup when generating the string for $stmt->bind_param. Code is as follows:

$stmt = $mysqli->stmt_init(); if ($stmt->prepare ($sql)) { $bind_types = '"'; $bind_values = '';

    if ($action == 'insert' || $action == 'update') {
        reset ($array);
        foreach ($array as $key => $value) {
            if (is_string ($value)) { $type = 's'; } else if (is_int ($value)) { $type = 'i'; } else if (is_float ($value)) { $type = 'd'; } else { die ('Cannot determine type for ' . $key . ' => ' . $value . ''); }
            $bind_types .= $type;
            $bind_values .= $value . ', ';
            //$stmt->bind_param ($type, $value);
        }
    }

    if ($action == 'update' || $action == 'delete') {
        if (is_string ($id_value)) { $type = 's'; } else if (is_int ($id_value)) { $type = 'i'; } else if (is_float ($id_value)) { $type = 'd'; } else { die ('Cannot determine type for ' . $id_column . ' => ' . $id_value . ''); }
        $bind_types .= $type;
        $bind_values .= $id_value . ', ';
        //$stmt->bind_param ($type, $id_value);
    }

    $bind_types .= '"';

    $bind_values = substr ($bind_values, 0, -2);

    echo $bind_types  . ', ' . $bind_values;

    $stmt->bind_param ($bind_types, $bind_values);
    $stmt->execute();

}

The formatting of that got messed up. I apologize if its hard to read.

I am getting the following error:

"Warning: mysqli_stmt::bind_param() [mysqli-stmt.bind-param]: Number of elements in type definition string doesn't match number of bind variables in ... "

Any ideas?

回答1:

I would highly advise to use PDO as you can do it easily. If you want to do it in mysqli it is more complicated since you can't easily bind them dynamically. To bind them dynamically look at this ugly hack

$bind_values= explode(',', $bind_values);
call_user_func_array(array($stmt, 'bind_param'), makeValuesReferenced($bind_values));
$stmt->execute();

function makeValuesReferenced(&$arr){ 
    $refs = array(); 
    foreach($arr as $key => $value) 
        $refs[$key] = &$arr[$key]; 
    return $refs; 

}

回答2:

Your call to bind_param is wrong: it should be:

bind_param($types, $value1, $value2, $value3 ...);

where each of those values is an actual variable.

来源：https://stackoverflow.com/questions/11533512/phps-mysqli-prepare-generate-dynamically

标签

php

mysqli