rmpotabitem

### 1) Overview
 The `rmpotabitem` table serves as the line-item detail repository for Raw Material Purchase Orders (RM PO). It stores specific data for each raw material associated with a Purchase Order, including quantities, unit rates, unit of measure (UOM), and technical specifications like HSN codes. It acts as the child table to `rmpotab` (the PO header) and links directly to the raw material master (`rmmas`) and brand master (`brandmas`).
 
 ### 2) Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Primary Key (Internal) | | Primary Key |
 | **compcode** | string | No | Company Identifier | e.g., 'DAS' | Join Key |
 | **pono** | integer | No | Purchase Order Number | | Join Key |
 | **rmcode** | string | No | Raw Material Code | e.g., 'S15C41' | Join Key / FK to `rmmas` |
 | **uom** | string | Yes | Unit of Measure | KGS, MTR | Descriptive |
 | **qty** | number | Yes | Ordered Quantity | | Aggregation |
 | **rmrate** | number | Yes | Rate per unit of Raw Material | | Commercial Calculation |
 | **invyear** | integer | No | Financial/Invoice Year | e.g., 2024 | Join Key |
 | **rmexdetail** | string | Yes | Extra item-level details/description | | Descriptive |
 | **br_code** | integer | Yes | Brand/Make Code | | FK to `brandmas` |
 | **hsn** | string | Yes | Harmonized System Nomenclature (Tax) | e.g., '72155090' | Tax Reporting |
 | **Lock** | string | Yes | Item Lock Status | 'N', Null | Logic Filtering |
 | **SNo** | number | Yes | Serial Number within the PO | | Ordering / Row ID |
 
 ### 3) Relationships & Join Map
 
 #### Parent Tables
 * **dbo.rmpotab**: The primary header table. Join on `compcode`, `pono`, and `invyear`.
 * **dbo.rmmas**: The Raw Material master. Join on `compcode` and `rmcode`.
 * **dbo.brandmas**: Contains manufacturer/brand names. Join on `compcode` and `br_code`.
 
 #### Child / Reference Tables
 * **dbo.rmincoming**: Records the actual receipt of materials against these PO lines. Join on `compcode`, `pono`, and `rmcode`.
 * **dbo.rmpotabitemamnd**: Contains the history of changes (amendments) for these specific items. Join on `compcode`, `pono`, and `rmcode`.
 * **dbo.scheduledtl**: Used in scheduling procurement. Join on `compcode` and `pono`.
 
 #### Recommended Joins (Strict)
 ```sql
 -- Fetching PO Details with Material Names
 SELECT a.pono, b.rmname, a.qty, a.rmrate
 FROM rmpotabitem a
 INNER JOIN rmmas b ON a.compcode = b.compcode AND a.rmcode = b.rmcode;
 
 -- Fetching PO Details with Brand/Make
 SELECT a.pono, a.rmcode, c.br_name
 FROM rmpotabitem a
 LEFT JOIN brandmas c ON a.compcode = c.compcode AND a.br_code = c.Br_code;
 
 -- Checking Balance (PO vs Incoming)
 SELECT a.pono, a.qty AS Ordered, SUM(i.billwt) AS Received
 FROM rmpotabitem a
 INNER JOIN rmincoming i ON a.compcode = i.compcode AND a.pono = i.pono AND a.rmcode = i.rmcode
 GROUP BY a.pono, a.qty;
 ```