Insert JSON value is failed about mysql

[demyan112rv]

@bwoebi thanks for the quick reply!

I added to create query SET utf8mb4 COLLATE = utf8mb4_unicode_ci and replace ? to CONVERT(? USING utf8mb4) in insert query.

This code is working good!

Amp\Loop::run(function () {

    $db = Amp\Mysql\pool("...");

    yield $db->query("CREATE TABLE IF NOT EXISTS amp_json (a INT(10), b JSON) CHARACTER SET utf8mb4 COLLATE = utf8mb4_unicode_ci;");

    /** @var \Amp\Mysql\Statement $statement */
    $statement = yield $db->prepare("INSERT INTO amp_json (a, b) VALUES (?, CONVERT(? USING utf8mb4))");
    foreach (range(1, 10) as $num) {
        $json = json_encode(['num' => $num]);
        yield $statement->execute([$num, $json]);
    }

    $db->close();
});

[bwoebi]

Does an explicit conversion in your query work? INSERT INTO amp_json (a, b) VALUES (?, CONVERT(? USING utf8mb4))

I could run your reproduce script without problems though - maybe you've messed your encoding up,, were you running the connection as binary? (Default is utf8mb4_general_ci)