hphp/hack/manual/apis/Classes/AsyncMysqlRowBlock/at.md
:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::
Get a field (column) value
public function at(
int $row,
mixed $field,
): mixed;
int $row - the row index.mixed $field - the field index (int) or field name (string).mixed - The value of the field (column) at the given row.The following example shows how to use AsyncMysqlRowBlock::at to get a field value from the resulting row block. In this case we are looking at the 0th element of the row block and wanting the age field.
use \Hack\UserDocumentation\API\Examples\AsyncMysql\ConnectionInfo as CI;
async function connect(
\AsyncMysqlConnectionPool $pool,
): Awaitable<\AsyncMysqlConnection> {
return await $pool->connect(
CI::$host,
CI::$port,
CI::$db,
CI::$user,
CI::$passwd,
);
}
async function simple_query(): Awaitable<int> {
$pool = new \AsyncMysqlConnectionPool(darray[]);
$conn = await connect($pool);
$result = await $conn->query('SELECT * FROM test_table WHERE userID < 50');
$conn->close();
// A call to $result->rowBlocks() actually pops the first element of the
// row block Vector. So the call actually mutates the Vector.
$row_blocks = $result->rowBlocks();
if ($row_blocks->count() > 0) {
// An AsyncMysqlRowBlock
$row_block = $row_blocks[0];
return (int)$row_block->at(0, "age");
} else {
return -1;
}
}
<<__EntryPoint>>
async function run(): Awaitable<void> {
$r = await simple_query();
\var_dump($r);
}
```.hhvm.expectf
int(%d)
```.example.hhvm.out
int(42)
```.skipif
await \Hack\UserDocumentation\API\Examples\AsyncMysql\skipif_async();