Notes

If you're working with a database in the command line (CMD), I assume you want to manage or interact with a database system, such as MySQL or PostgreSQL. Here's an example of how to create and manage **Customer**, **Account**, and **Branch** tables in a database using MySQL commands:

### 1. **Create Database**:
First, create the database:

```sql
CREATE DATABASE BankDB;
USE BankDB;
```

### 2. **Create Tables**:
Now, let's create the tables for **Customer**, **Account**, and **Branch**.

#### Customer Table:
```sql
CREATE TABLE Customer (
customer_id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(50),
address VARCHAR(100),
phone_number VARCHAR(15)
);
```

#### Account Table:
```sql
CREATE TABLE Account (
account_id INT PRIMARY KEY AUTO_INCREMENT,
customer_id INT,
account_type VARCHAR(10),
balance DECIMAL(10, 2),
FOREIGN KEY (customer_id) REFERENCES Customer(customer_id)
);
```

#### Branch Table:
```sql
CREATE TABLE Branch (
branch_id INT PRIMARY KEY AUTO_INCREMENT,
branch_name VARCHAR(50),
branch_address VARCHAR(100)
);
```

### 3. **Insert Data**:
Now, let's insert some sample data into these tables.

#### Insert into Customer:
```sql
INSERT INTO Customer (name, address, phone_number)
VALUES ('John Doe', '123 Main St', '555-1234'),
('Jane Smith', '456 Oak St', '555-5678');
```

#### Insert into Account:
```sql
INSERT INTO Account (customer_id, account_type, balance)
VALUES (1, 'Savings', 5000.00),
(2, 'Checking', 3000.00);
```

#### Insert into Branch:
```sql
INSERT INTO Branch (branch_name, branch_address)
VALUES ('Main Branch', '789 Elm St'),
('West Branch', '101 Pine St');
```

### 4. **Query Data**:
You can then retrieve data with SQL queries.

#### Example - Fetch all customers:
```sql
SELECT * FROM Customer;
```

#### Example - Fetch accounts with customer info:
```sql
SELECT a.account_id, a.account_type, a.balance, c.name
FROM Account a
JOIN Customer c ON a.customer_id = c.customer_id;
```

Let me know if you need more customization or specific queries!