does not import data into the operations table

i want to do trigger code with import updates and inserts (table doctors to table logs(all operations when i update or delete)

DROP database IF EXISTS vk;
CREATE database vk;
USE vk;

DROP table IF EXISTS doctors;   
create table doctors(
 id int unsigned primary key not null unique auto_increment, 
 name varchar(15) comment "Имя" not null,
 sacond_name varchar(50) comment "Фамилия" not null,
 patronimic varchar(50) comment "Отчество"
); 
alter table doctors  add telephone int unsigned;

CREATE TABLE IF NOT EXISTS logs (
    log_id INT AUTO_INCREMENT PRIMARY KEY,
    table_name VARCHAR(255),
    operation_type VARCHAR(10),
    old_data TEXT,
    new_data TEXT,
    operation_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

DELIMITER ;;

CREATE TRIGGER doctors_update AFTER INSERT ON logs 
  FOR EACH ROW BEGIN 
end;;

-- this trigger is work but it dont import data to table logs

DELIMITER $$
CREATE TRIGGER Doctor_insert_trig AFTER INSERT ON doctors FOR EACH row
BEGIN
    INSERT INTO logs (table_name, operation_type, new_data, operation_date)
    VALUES ('doctors', 'INSERT', 
            CONCAT('{"id": ', NEW.id, ', "name": "', NEW.name, '", "sacond_name": "', NEW.sacond_name, '", "patronimic": "', NEW.patronimic, '"}'), 
            NOW());
end;
DELIMITER ;

-- I already tried to do this with the import, but an error was written

SQL Error [1064] [42000]: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 6

Error position: line: 5

made trigger to import delete on updates data of table doctors to table logs