CREATE TABLE IF NOT EXISTS admin_balance_request (
 admin_id BIGINT NOT NULL,
 operation VARCHAR(16) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
 request_id VARCHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
 payload TEXT NOT NULL,
 completed TINYINT(1) NOT NULL DEFAULT 0,
 created_time DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
 PRIMARY KEY(admin_id,operation,request_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
-- Keep records: deleting a completed key allows that request to be executed again.