# GetPartnerBankAccount

## Overview

GetPartnerBankAccount retrieves a single bank account record by id. This serves as the lookup for update, delete, and setDefault bank account commands.

## Business Rules

- Accepts `{ id }` as input — retrieves by unique identifier
- Returns the full PartnerBankAccount record or null if no matching bank account is found
- Used by update, delete, and setDefault commands to verify the bank account exists before operating on it

## Process Flow

```mermaid
flowchart TD
    A[Receive input] --> B[SELECT from PartnerBankAccount where id = input.id]
    B --> C{Bank account found?}
    C -->|Yes| D[Return bank account record]
    C -->|No| E[Return null]
```

## External Dependencies

- None

## Error Scenarios

- **BANK_ACCOUNT_NOT_FOUND**: Specified bank account ID does not exist

## Test Cases

- returns bank account when found
- returns null when not found
