Write a SQL query using a window function to rank employees by sales within each department.
Use the provided employee and sales data. Calculate each employee's total sales, include employees with no sales, and assign the same rank to employees tied on total sales.
employee_id, employee_name, department, total_sales, and sales_rank.| Column | Type | Description |
|---|---|---|
| employee_idPK | INT | Unique employee identifier |
| employee_name | VARCHAR(100) | Employee's full name |
| department | VARCHAR(100) | Employee department |
| Column | Type | Description |
|---|---|---|
| sale_idPK | INT | Unique sale identifier |
| employee_id | INT | Employee credited with the sale |
| sale_amount | NUMERIC(12,2) | Amount of the sale |