last_query
返回最后一条执行的SQL语句.
last_query()
Return: [string]
和log()很相似，但只返回最后一次执行的SQL语句
$database->select("account", [
"user_name",
"email"
], [
"user_id[<]" => 20
]);
$database->insert("account", [
"user_name" => "foo",
"email" => "foo@bar.com"
]);
echo $database->last_query();
// INSERT INTO "account" ("user_name", "email") VALUES ('foo', 'foo@bar.com')