pmchdr2

### 1) Overview
 The `pmchdr2` table serves as the **Production Issue Header for 2nd Operations**. It records the issuance of semi-finished items to specific machines (`mccode`) for subsequent manufacturing processes (`oprcode`). In the production workflow, this table tracks quantities (`pcs`), specific batches (`lotno`, `heatno`), and operational parameters before they are recorded as finished production in the `product1` table.
 
 It is frequently used in conjunction with `mchdr` (which typically handles 1st/Initial operations) to provide a complete view of the manufacturing history and work-in-progress (WIP) status of an item across multiple stages.
 
 ### 2) Column Dictionary
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Primary Key | | Internal identifier. |
 | **compcode** | string | No | Company Code | e.g., "DAS", "BPL" | Filter for multi-tenant data. |
 | **issueno** | integer | No | Issue Number | | Unique ID for the issue document; links to production logs. |
 | **prdate** | datetime | No | Production/Process Date | | Used for chronological reporting and month-end audits. |
 | **mccode** | string | No | Machine Code | e.g., "TRB1", "CNC50" | Joins to `dbo.machine` to identify physical equipment. |
 | **itemcode** | string | No | Part/Item Identifier | e.g., "CP-058" | Primary link to `dbo.itemmas`. |
 | **lotno** | string | Yes | Batch/Lot Number | | Tracks material traceability. |
 | **pcs** | number | Yes | Quantity in Pieces | | The total count issued for the operation. |
 | **weight** | number | Yes | Quantity by Weight | | Secondary unit of measure tracking. |
 | **remarks** | string | Yes | Internal Notes | | Audit or process exceptions. |
 | **itemcode1** | string | Yes | Required/Parent Item Code | | Often used in views to show the "Item Required" vs "Item Produced". |
 | **oprcode** | string | No | Operation Code | e.g., "CNC1", "MS" | Joins to `dbo.oprmas` to identify the manufacturing step. |
 | **username** | string | Yes | Entry User | | Audit tracking. |
 | **printflag** | string | Yes | Printed Status | | Tracking document generation. |
 | **sublotno** | string | Yes | Sub-Batch Identifier | | Detailed traceability. |
 | **heatno** | string | Yes | Raw Material Heat Number | | Link to metallurgical properties. |
 | **variant** | string | Yes | Product Variant | | Differentiation within a part number. |
 | **uom** | string | Yes | Unit of Measure | "PCS", "KGS" | Defines how `pcs` and `weight` are interpreted. |
 | **cw** | number | Yes | Conversion Weight | | Used to calculate piece counts when weight is provided (PCS = Wt * 1000 / CW). |
 | **location** | string | Yes | Physical Location Code | | Joins to `dbo.PhyLocation`. |
 | **TrfFromProdNo**| string | Yes | Transfer Source | | Tracks material movement from a prior production run. |
 
 ### 3) Relationships & Join Map
 
 #### Primary Links (Header to Detail/Production)
 * **dbo.product1**: Joins on `issueno` and `compcode`. This is the most critical relationship, linking the "Issue" of material to the "Resulting Production" (Accepted, Rejected, and Scrap quantities).
 * **dbo.pmcdtl2**: Joins on `issueno` and `compcode`. Provides specific attributes (grade, hardness) for the issue header.
 
 #### Master Data Joins
 * **dbo.itemmas**: Joins on `itemcode` (or `itemcode1`) to retrieve descriptions, part numbers, and weights.
 * **dbo.machine**: Joins on `mccode` and `compcode` to identify the specific machine or work center where the issue was allocated.
 * **dbo.oprmas**: Joins on `oprcode` and `compcode` to retrieve operation descriptions (e.g., "Milling", "CNC Turning").
 * **dbo.itemopr**: Joins on `itemcode` AND `oprcode` to retrieve the standard operation routing and piece weights (`oprweight`).
 
 #### Likely Inventory/WIP Joins
 * **dbo.job**: Joined in outward views (e.g., `viewlotnooutward`) to compare in-house production issues against job-work issues sent to vendors.
 * **dbo.onlinerej_dtl**: Linked via `itemcode` and `oprcode` in balancing procedures to calculate remaining WIP by subtracting scrapped or rejected units from the issued amount.