itemvendopr

### 1) Overview
 The `itemvendopr` table serves as a **Vendor-Operation Rate Master**. It defines the specific financial and operational contract between the company, a vendor, and a specific manufacturing process (operation) for a particular item. 
 
 In a SQL Server environment, this table is critical for:
 * **Job Work Valuation:** Determining the cost of outsourced labor or processes (e.g., CNC machining, hardening, milling) by looking up the `oprrate`.
 * **Billing Validation:** Comparing incoming vendor invoices against the agreed `billrate`.
 * **Authorization:** Filtering active contracts using the `auth_flag`.
 
 The table uses a composite logical key consisting of `compcode`, `itemcode`, `vendcode`, and `oprcode`.
 
 ### 2) Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | NO | Primary Key (Internal) | Incremental integers | Unique record identification. |
 | **compcode** | string | NO | Company Identifier | e.g., "DAS" | Primary filter for multi-tenant environments. |
 | **itemcode** | string | NO | Unique Item Identifier | e.g., "CCP", "CP-003" | Join key to `itemmas` and production tables. |
 | **vendcode** | string | NO | Unique Vendor Identifier | e.g., "BPPL", "SSW" | Join key to `vendmas` and purchase headers. |
 | **oprcode** | string | NO | Operation/Process Code | e.g., "CNC1", "HARD" | Join key to `oprmas` or `itemopr`. |
 | **oprrate** | number | YES | Process Rate (Internal Cost) | e.g., 40.0, 7.25 | Used in COGS and Job Work calculations. |
 | **billrate** | number | YES | Agreed Billing Rate | e.g., 1.54, 11.0 | Used to validate Vendor Invoices. |
 | **UoM** | string | YES | Unit of Measure | KGS, PCS | Defines the scale of the rates. |
 | **auth_flag** | string | YES | Authorization Status | Y, N | Filter for active/authorized rates. |
 
 ### 3) Relationships & Join Map
 
 The `itemvendopr` table acts as a bridge between Material Masters and Vendor Masters for specific production steps.
 
 #### Authoritative Joins (via SCHEMA_MAP):
 
 * **Item Master (`dbo.itemmas`)**:
  * `itemvendopr.itemcode` -> `itemmas.itemcode`
  * `itemvendopr.compcode` -> `itemmas.compcode`
  * *Usage:* To fetch item descriptions or categories for a vendor rate.
 
 * **Vendor Master (`dbo.vendmas`)**:
  * `itemvendopr.vendcode` -> `vendmas.vendcode`
  * `itemvendopr.compcode` -> `vendmas.compcode`
  * *Usage:* To fetch vendor names and tax registration details for billing.
 
 * **Operation Master (`dbo.oprmas`)**:
  * `itemvendopr.oprcode` -> `oprmas.oprcode`
  * `itemvendopr.compcode` -> `oprmas.compcode`
  * *Usage:* To retrieve the full name/description of the process (e.g., "CNC Machine 1").
 
 * **Material Receipt (Job Work) (`dbo.mrci2dtl` / `dbo.mrcirdtl`)**:
  * `itemvendopr.itemcode` -> `mrci2dtl.itemcode`
  * `itemvendopr.oprcode` -> `mrci2dtl.oprcode`
  * `itemvendopr.compcode` -> `mrci2dtl.compcode`
  * *Likely Join (via Stored Proc):* Often joined with `mrci_rep` (Header) on `vendcode` to apply the rate to received quantities.
 
 * **Job Order Details (`dbo.jobpodtl`)**:
  * `itemvendopr.itemcode` -> `jobpodtl.itemcode`
  * `itemvendopr.oprcode` -> `jobpodtl.oprcode`
  * `itemvendopr.compcode` -> `jobpodtl.compcode`
  * *Usage:* To auto-populate or validate rates on Purchase Orders (Job Cards).