sfpoitem

### 1. Overview
 The `sfpoitem` table serves as the line-item detail repository for **Semi-Finished (SF) Purchase Orders**. It stores the specific item codes, quantities, rates, and tax-related HSN codes associated with a parent Purchase Order record. Each row represents a single item entry within a PO, uniquely identified by a combination of the company code, purchase order number, financial year, and item code.
 
 ### 2. Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Internal primary key / Physical row index | | Primary Key |
 | **compcode** | string | No | Unique identifier for the company | e.g., "DAS" | Join; Filter |
 | **pono** | integer | No | Purchase Order Number | | Join; Filter |
 | **itemcode** | string | No | Unique code for the Semi-Finished item | | Join; Filter |
 | **uom** | string | Yes | Unit of Measure | PCS, NOS | Reporting |
 | **qty** | number | Yes | Quantity of items ordered | | Calculations |
 | **itemrate** | number | Yes | Unit price/rate of the item | | Calculations |
 | **invyear** | integer | No | Financial/Invoice year associated with the PO | e.g., 2013, 2023 | Join; Partitioning |
 | **itemexdetail** | string | Yes | Extended item description or special instructions | | Reporting |
 | **hsn** | string | Yes | Harmonized System of Nomenclature code for GST | | Taxation |
 | **Lock** | string | Yes | Status flag indicating if the record is locked | 'N', Null | Logic Control |
 | **SNo** | number | Yes | Serial number of the item within the specific PO | | Ordering |
 
 ### 3. Relationships & Join Map
 
 The table primarily acts as a child to Purchase Order headers and a consumer of Item Master data.
 
 #### Primary Joins (Strictly based on SCHEMA_MAP):
 * **sfpo** (PO Header): Join via `compcode`, `pono`, and `invyear`. This is the standard parent-child relationship for PO processing.
 * **itemmas** (Item Master): Join via `compcode` and `itemcode`. Used to retrieve detailed item names, part numbers, and specifications.
 * **sfpoitemamnd** (PO Item Amendments): Join via `compcode`, `pono`, `invyear`, and `itemcode`. Used to compare current PO values against previous amendments.
 * **fghdr** (Finished Goods/Receipts): Join via `compcode`, `pono`, and `itemcode`. Used to calculate the balance quantity (Ordered vs. Received).
 * **sfindentitem** (SF Indent Details): Joins via `compcode` and `itemcode` (and `indentno` through `sfpo`). Used to track POs generated against specific indents.
 
 #### Likely Joins (Inferred):
 * **chapter**: Join via `hsn` (sfpoitem) to `chapter` (chapter) to determine applicable tax rates.
 * **suppmas**: Joined indirectly through `sfpo` (using `supcode`) to fetch supplier details like names and addresses.