Section 1: DDL

CREATE TABLE `deposit_types` (
    `deposit_type_id` INT,
    `name` VARCHAR(20),
    CONSTRAINT `pk_deposit_types` PRIMARY KEY (`deposit_type_id`)
);

CREATE TABLE `deposits` (
    `deposit_id` INT AUTO_INCREMENT,
    `amount` DECIMAL(10 , 2 ),
    `start_date` DATE,
    `end_date` DATE,
    `deposit_type_id` INT,
    `customer_id` INT,
    CONSTRAINT `pk_deposits` PRIMARY KEY (`deposit_id`),
    CONSTRAINT `fk__deposits_deposit_types` FOREIGN KEY (`deposit_type_id`)
        REFERENCES `deposit_types`(`deposit_type_id`),
    CONSTRAINT `fk_deposits_customers` FOREIGN KEY (`customer_id`)
        REFERENCES `customers`(`customer_id`)
);

CREATE TABLE `employees_deposits` (
    `employee_id` INT,
    `deposit_id` INT,
    CONSTRAINT `pk_employees_deposits` PRIMARY KEY (`employee_id` , `deposit_id`),
    CONSTRAINT `fk_employees_deposits_employees` FOREIGN KEY (`employee_id`)
        REFERENCES `employees` (`employee_id`),
    CONSTRAINT `fk_employees_deposits_deposits` FOREIGN KEY (`deposit_id`)
        REFERENCES `deposits` (`deposit_id`)
);

CREATE TABLE `credit_history` (
    `credit_history_id` INT,
    `mark` CHAR(1),
    `start_date` DATE,
    `end_date` DATE,
    `customer_id` INT,
    CONSTRAINT `pk_credit_history` PRIMARY KEY (`credit_history_id`),
    CONSTRAINT `fk_credit_history_customers` FOREIGN KEY (`customer_id`)
        REFERENCES `customers` (`customer_id`)
);

CREATE TABLE `payments` (
    `payement_id` INT,
    `date` DATE,
    `amount` DECIMAL(10 , 2 ),
    `loan_id` INT,
    CONSTRAINT `pk_payments` PRIMARY KEY (`payement_id`),
    CONSTRAINT `fk_payments_loans` FOREIGN KEY (`loan_id`)
        REFERENCES `loans` (`loan_id`)
);

CREATE TABLE `users` (
    `user_id` INT,
    `user_name` VARCHAR(20),
    `password` VARCHAR(20),
    `customer_id` INT UNIQUE,
    CONSTRAINT `pk_users` PRIMARY KEY (`user_id`),
    CONSTRAINT `fk_users_customers` FOREIGN KEY (`customer_id`)
        REFERENCES `customers` (`customer_id`)
);


ALTER TABLE `employees`
ADD `manager_id` INT,
ADD CONSTRAINT `fk_employees_employees` FOREIGN KEY(`manager_id`)
REFERENCES `employees`(`employee_id`);