invdtl

### 1) Overview
 The `invdtl` table serves as the primary line-item detail repository for sales invoices within the ERP system. It records specific transaction data for each item sold, including quantities, unit rates, discounts, and item-level tax distributions (CGST, SGST, IGST).
 
 The table is fundamentally linked to `invhdr` (Invoice Header) via a composite key of `compcode`, `invno`, and `invyear`. It supports various business processes including domestic sales, export sales, raw material sales, and job work-related invoicing. Traceability features such as `lotno`, `HeatNo`, and `PDIRNo` (Pre-Despatch Inspection Report) are included to ensure quality control standards are met during the shipping process.
 
 ### 2) Column Dictionary
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Primary Key | | Filter: `WHERE index = ...` |
 | **compcode** | string | No | Company Identifier | e.g., "DAS", "BAM" | Join: `invhdr`, `saleitemmas` |
 | **invno** | integer | No | Invoice Number | | Join: `invhdr`, `invtax` |
 | **invyear** | integer | No | Financial Year of Invoice | e.g., 2013, 2024 | Join: `invhdr`, `invtax` |
 | **itemcode** | string | No | Unique Item/Product Code | e.g., "CP-088" | Join: `saleitemmas`, `itemmas` |
 | **partno** | string | Yes | Customer Part Number | | Joins/Display |
 | **itemqty** | number | Yes | Quantity invoiced | | Aggregation: `SUM(itemqty)` |
 | **itemrate** | number | Yes | Unit price per item | | Calculation: `itemqty * itemrate` |
 | **uom** | string | Yes | Unit of Measure | e.g., "Nos", "PCS", "KGS" | Join logic (KGS/MTR vs Nos) |
 | **itemdisc** | number | Yes | Discount percentage or amount | | Calculation |
 | **itemamt** | number | Yes | Total amount for the line item (Pre-tax) | | Aggregation: `SUM(itemamt)` |
 | **noofcases** | integer | Yes | Number of packing cases/cartons | | Calculation |
 | **sno** | integer | Yes | Serial Number (Line sequence) | | Sorting |
 | **pageno** | string | Yes | Reference page in invoice documents | | Display |
 | **ct3no** | string | Yes | CT-3 certificate number (Exemption) | | Regulatory reporting |
 | **packdetail** | string | Yes | Packaging specifics | | Display |
 | **packmode** | string | Yes | Mode of packing | | Filter |
 | **pitemcode** | string | Yes | Parent Item Code (Likely) | | Relationship logic |
 | **pono** | string | Yes | Customer Purchase Order Reference | | Join: `podtl` |
 | **noofbox** | string | Yes | Number of boxes | | Display |
 | **mrpno** | integer | Yes | Material Receipt/RM Batch reference | | Join: `rmincoming`, `rmjobrec1st` |
 | **cgst_per** | string | Yes | CGST Tax Percentage | | Calculation |
 | **cgst_amt** | string | Yes | CGST Tax Amount | | Aggregation |
 | **sgst_per** | string | Yes | SGST Tax Percentage | | Calculation |
 | **sgst_amt** | string | Yes | SGST Tax Amount | | Aggregation |
 | **igst_per** | string | Yes | IGST Tax Percentage | | Calculation |
 | **igst_amt** | string | Yes | IGST Tax Amount | | Aggregation |
 | **hsn** | string | Yes | Harmonized System Nomenclature code | e.g., "87089900" | Join: `chapter` |
 | **taxableamount** | string | Yes | Net taxable value after discounts | | Aggregation |
 | **invclose** | string | Yes | Status flag for item closure | 'Y', 'N' | Filter |
 | **lotno** | string | Yes | Manufacturing Lot Number | | Traceability |
 | **custcode** | string | Yes | Customer Identifier | e.g., "APL" | Join: `cust` |
 | **Suplitemrate** | string | Yes | Supplementary Item Rate | | Display |
 | **Suplamndno** | string | Yes | Supplementary Amendment Number | | Display |
 | **amndno** | string | Yes | Amendment Number | | Versioning |
 | **amnddate** | string | Yes | Amendment Date | | Versioning |
 | **PDIRNo** | string | Yes | Pre-Despatch Inspection Report Number | | Traceability |
 | **PDIRDate** | string | Yes | PDIR Date | | Display |
 | **HeatNo** | string | Yes | Raw Material Heat Number | | Traceability |
 | **tcsamt** | number | Yes | Tax Collected at Source Amount | | Aggregation |
 | **Gross_Rate** | number | Yes | Rate including certain components | | Display |
 | **ItemName** | string | Yes | Product Description | | Display |
 | **RMC** | string | Yes | Raw Material Cost (Likely) | | Analysis |
 | **RMC_RMRate** | string | Yes | Rate of RM used in product | | Analysis |
 | **RMC_ConvCharges** | string | Yes | Conversion charges for product | | Analysis |
 | **ManufacturingDate**| string | Yes | Date of manufacture | | Traceability |
 | **ExpiryDate** | string | Yes | Product expiry date | | Traceability |
 
 ### 3) Relationships & Join Map
 
 #### Authoritative Joins (Schema Map)
 * **invhdr**: Join via `compcode`, `invno`, and `invyear`. This provides access to invoice dates, customer details, and invoice status flags.
 * **saleitemmas**: Join via `compcode` and `itemcode`. Used to retrieve master product descriptions (`salesname`), weights (`finishwt`), and category information.
 * **cust**: Join via `compcode` and `custcode` to get customer names, addresses, and GST status.
 * **invtax**: Join via `compcode`, `invno`, `invyear`, and `sno`. This is used to link specific tax duties associated with the invoice line.
 * **podtl**: Join via `compcode`, `custcode`, `pono`, and `itemcode` to reconcile against the original Customer Purchase Order.
 
 #### Functional Joins (Likely)
 * **rmincoming**: Join via `compcode` and `mrpno` (matching `mrpno` in `invdtl`). Primarily used when selling raw materials or items with strict RM traceability.
 * **rmjobrec1st**: Join via `compcode` and `mrpno`. Used in Job Work scenarios to track the return of processed material to the customer.
 * **pdiinspectionhdr**: Join via `compcode`, `invno`, and `invyear`. Links to pre-despatch inspection metadata.
 * **invlotdetail**: Join via `compcode`, `invno`, `invyear`, and `itemcode`. Provides granular lot tracking for specific items.
 
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