README

Render queryf-style SQL queries to strings for logging and debugging.

SqlQueryf\ToString\engine() will render queries for logging and debugging purposes. For example, if you have a syntax error in the query you just ran, you might want to add the query to the exception message to aid the developer in fixing it.

Security Notice

SqlQueryf\ToString\engine() is meant for logging and debugging. Do NOT pass the returned query to a database. This is a bad idea, since SQL escaping has been mocked out with fake_mysql_escape_UNSAFE. Please for all that is good, don't!

Why don't I use HH\Lib\SQL\Query’s built-in methods?

If your application uses HH\Lib\SQL\Query, and want to use toString__FOR_DEBUGGING_ONLY for this purpose, you might tear down your entire hhvm instance with a segmentation fault. This method is broken and should not be used. The method toUnescapedString__FOR_DEBUGGING_ONLY__UNSAFE does work, but the result is very difficult to read. Strings with quotes or slashes break the SQL syntax and the renderer tries to save bytes by inserting as little whitespace as possible.

Migration

If you use HH\Lib\SQL\Query, create these functions in your namespace:

type QueryType = SQL\Query;

function queryf(
  HH\FormatString<SQL\QueryFormat> $format,
  mixed ...$args
)[defaults]: QueryType {
  return \HH\FIXME\UNSAFE_CAST<dynamic, dynamic>(SQL\Query::class)
    |> new $$($format, $args);
}

function query_to_native(QueryType $query)[]: SQL\Query {
  return $query;
}

Replace usages of new SQL\Query() with queryf() and $db->queryAsync($q) with $db->queryAsync(query_to_native($q)). Then replace references to the SQL\Query type with the QueryType type. This will change nothing about your application.

You are now ready to make the switch to:

type QueryType = SqlQueryf\HipHopLibSqlQueryPack;

function queryf(
  HH\FormatString<ToString\Sql> $format,
  mixed ...$args
)[]: SqlQueryf\HipHopLibSqlQueryPack {
  return SqlQueryf\HipHopLibSqlQueryPack::createWithoutTypechecking_UNSAFE(
    $format as string,
    vec($args),
  );
}

function query_to_native(
  SqlQueryf\HipHopLibSqlQueryPack $query,
)[defaults]: SQL\Query {
  $args = vec[];

  foreach ($pack->getArguments() as $a) {
    if ($a is SqlQueryf\HipHopLibSqlQueryPack) {
      $args[] = query_to_native($a);
    } else {
      $args[] = $a;
    }
  }

  return \HH\FIXME\UNSAFE_CAST<dynamic, dynamic>(SQL\Query::class)
    |> new $$($pack->getFormat(), $args);
}

Use of the __FOR_DEBUGGING_ONLY methods will now be a type error. Replace them with a call to:

function queryf_to_string(
  SqlQueryf\HipHopLibSqlQueryPack $query
)[]: string {
  return ToString\engine($query->getFormat(), $query->getArguments())
    |> \vsprintf(...$$);
}

Congratulations on a successful migration.

Expanding the possibilities

Now that you own the HH\FormatString<T> type for your queries, you may want to add specifiers that are not part of the set provided by SQL\Query. You can create any engine() and transform from QueryPack to SQL\Query.