saleappdutymas

### 1) Overview
 The `saleappdutymas` table serves as a mapping or junction table within the Sales/Tax module. It defines the relationship between primary **Duty Codes** (representing tax categories or groups) and their specific **Applicable Duty Codes** (representing individual tax components like GST, VAT, or Surcharges). 
 
 This table allows the system to determine which sub-taxes or related duties should be triggered or calculated when a specific primary tax group is applied to a transaction. It is specifically used for sales-related tax configurations.
 
 ### 2) Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | NO | Primary Key (technical) | Auto-incrementing IDs | `WHERE index = 10` |
 | **compcode** | string | NO | Company Identifier | e.g., "DAS" | `ON a.compcode = b.compcode` |
 | **duty_code** | integer | NO | Primary Duty/Tax Code Group | e.g., 7, 11, 15 | `JOIN saledutymas ON ...` |
 | **app_duty_code** | integer | NO | Sub-Duty or Component Duty Code | e.g., 1, 5, 25 | `JOIN saledutymas ON ...` |
 
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 ### 3) Relationships & Join Map
 
 #### Logical Relationships
 * **One-to-Many**: One `duty_code` (Primary Group) maps to multiple `app_duty_code` (Tax Components).
 * **Hierarchical**: This table creates a hierarchy for tax calculation in sales invoices.
 
 #### Strict Join Map (Based on SCHEMA_MAP)
 
 1. **saledutymas (Master Tax Definitions)**
  * **Join Column**: `duty_code` (and/or `app_duty_code`)
  * **Usage**: To retrieve the names and calculation rules (nature, sequence, roff) for the codes listed in this table.
  * **SQL**: `saleappdutymas.duty_code = saledutymas.duty_code`
 
 2. **dutymas (Generic Duty Master)**
  * **Join Column**: `duty_code`
  * **Usage**: General duty attributes (HSN, Tax Rate).
  * **SQL**: `saleappdutymas.duty_code = dutymas.duty_code`
 
 3. **invtax (Invoice Tax Details)**
  * **Join Column**: `duty_code`
  * **Usage**: Link applicable duty configurations to actual values calculated on specific invoices.
  * **SQL**: `saleappdutymas.duty_code = invtax.duty_code`
 
 4. **TEMPSALEREGISTER (Reporting)**
  * **Join Column**: `compcode` (Likely column-based logic)
  * **Usage**: The columns `sale1amt` through `sale25amt` in `TEMPSALEREGISTER` likely correspond to the numeric IDs found in `app_duty_code`.