PHP mysql inset

<?php
// Simple clean insert
$sql = 'INSERT INTO `posts` (`title`, `content`) VALUES ("' . mysql_real_escape_string($_POST['post_title']) .'", "' . mysql_real_escape_string($_POST['post_content']) .'")';
if (!mysql_query($sql)) {
    error_log('oops in sql query:' . mysql_error() . ' | the query was:' . $sql);
}
?>

// Simple output
<input type="post_title" name="title" value="<?php echo htmlspecialchars($postRow['post_title']); ?>">
<textarea name="post_content"><?php echo htmlspecialchars($postRow['post_content']); ?></textarea>