text: create table oauth_clients (
    id INT NOT NULL PRIMARY KEY AUTO_INCREMENT, 
    client_id VARCHAR(320) NOT NULL, 
    client_secret VARCHAR(36) NOT NULL, 
    grant_type ENUM('CLIENT_CREDENTIALS'), 
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL,
    updated_at DATETIME NULL on UPDATE CURRENT_TIMESTAMP,
    CONSTRAINT oauth_clients_client_id UNIQUE (client_id), 
    INDEX(client_id),
    INDEX(client_secret)
  );
  