invdespdtl

### 1) Overview
 The `invdespdtl` table stores the line-item details for despatch invoices, primarily focused on Job Work (JW) transactions. Unlike standard sales invoices that often list just the finished product, this table captures the specific operations (e.g., Cold Forging, CNC Turning, Drilling) performed on items, their corresponding quantities (`despqty`), and the specific operation rates (`oprrate`). It serves as the granular breakdown for `invdesphdr`.
 
 ### 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", "SAP" | Join key |
 | **invno** | integer | No | Invoice Number | | Join key |
 | **invyear** | integer | No | Financial year of the invoice | e.g., 2019, 2022 | Join key |
 | **oprcode** | string | Yes | Operation code performed on the item | e.g., "CF", "CNC1", "DRIL" | Join key |
 | **withoutopr** | string | Yes | Flag indicating if transaction is without specific operation charges | "N", "Y" | Filtering |
 | **oprrate** | number | Yes | Unit rate for the specific operation | | Calculated fields |
 | **itemcode** | string | Yes | Internal code for the part/item | e.g., "CP-002" | Join key |
 | **uom** | string | Yes | Unit of Measure | e.g., "PCS" | Descriptive |
 | **despqty** | number | Yes | Quantity despatched for this specific operation/item | | Aggregations (SUM) |
 | **remarks** | string | Yes | Line-level internal comments | | Descriptive |
 | **rework** | string | Yes | Flag indicating if the line item is for rework | "N", "Y" | Filtering |
 | **cgst_PER** | string | Yes | Central GST Percentage | | Financials |
 | **sgst_PER** | string | Yes | State GST Percentage | | Financials |
 | **igst_PER** | string | Yes | Integrated GST Percentage | | Financials |
 | **cgst_amt** | string | Yes | Central GST calculated amount | | Financials |
 | **sgst_amt** | string | Yes | State GST calculated amount | | Financials |
 | **igst_amt** | string | Yes | Integrated GST calculated amount | | Financials |
 | **sno** | integer | Yes | Serial number / Line item sequence | | Sorting |
 | **ItemAmt** | number | No | Total amount for this line (`despqty` * `oprrate`) | | Financials |
 | **ItemName** | string | Yes | Descriptive name of the item | | Reporting |
 | **oprname** | string | Yes | Descriptive name of the operation | | Reporting |
 | **HSN** | string | Yes | GST HSN classification code | e.g., "998898" | Regulatory |
 
 ### 3) Relationships & Join Map
 
 #### Primary Header Relationship
 * **invdesphdr**: Joins on `compcode`, `invno`, and `invyear`. This links the detail lines to the main invoice header (customer info, total value, dates).
 
 #### Master Data Relationships
 * **itemmas**: Joins on `compcode` and `itemcode`. Used to retrieve detailed part specifications and `partno`.
 * **oprmas**: Joins on `compcode` and `oprcode`. Used to retrieve standard operation names and details.
 * **itemopr**: Joins on `compcode`, `itemcode`, and `oprcode`. Used to validate operation rates and machine associations.
 
 #### Likely Joins (Inferred from context)
 * **invdespwodetail**: Likely joins on `compcode`, `invno`, and `invyear` to link work order specifics to the invoice line.
 * **lablenumbers**: Likely joins on `compcode`, `invno`, and `invyear` to correlate specific labels printed for the despatch.