itemsup

### 1. Overview
 The `itemsup` table serves as a **Supplier-Item Cross-Reference (SXR)** or **Approved Vendor List (AVL)**. It establishes specific procurement terms between the organization and its vendors. Its primary function is to store pre-negotiated unit rates, discounts, and supplier-specific part numbers for items, facilitating automated pricing during the creation of Purchase Orders (PO) or Indents.
 
 ### 2. Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **compcode** | string | No | Unique identifier for the company/legal entity. | e.g., "DAS" | Primary Join Key |
 | **itemcode** | string | No | Internal unique identifier for the material or product. | e.g., "THIMBLE07" | Join to `itemmas` |
 | **supcode** | string | No | Unique identifier for the supplier or vendor. | e.g., "GANESHELEC" | Join to `suppmas` |
 | **rate** | number | Yes | The negotiated unit price for the item from this specific supplier. | e.g., 30.62 | Procurement Costing |
 | **discount** | number | Yes | Standard discount percentage offered by the supplier for this item. | e.g., 25.0 | Pricing Logic |
 | **br_code** | integer | Yes | Brand Code or Branch Code associated with the item-supplier link. | e.g., 270 | Join to `brandmas` |
 | **partno** | string | Yes | The supplier's internal part number or catalog reference. | e.g., "PN-123" | Reference / Printing |
 
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 ### 3. Relationships & Join Map
 
 The table acts as a bridge between the Item Master and Supplier Master, often used in Purchasing modules to validate vendor eligibility for specific items.
 
 #### Primary Joins (Authoritative):
 * **Item Master:** Join `dbo.itemsup` to `dbo.itemmas` on `(compcode, itemcode)`. This retrieves item descriptions, categories, and units of measure.
 * **Supplier Master:** Join `dbo.itemsup` to `dbo.suppmas` on `(compcode, supcode)`. This retrieves supplier names, addresses, and tax registration details (GST/PAN).
 * **Brand Master:** Join `dbo.itemsup` to `dbo.brandmas` on `(compcode, br_code)`. This identifies the specific manufacturer/brand associated with the supplier's offering.
 
 #### Secondary Joins (Functional):
 * **Purchase Orders (CPOHDR):** Join `dbo.itemsup` to `dbo.cpohdr` on `(compcode, supcode)` to validate if a vendor being used in a PO has a pre-defined rate for the items being ordered.
 * **Item Inspection (ItemInspectionHdr):** Join `dbo.itemsup` to `dbo.iteminspectionhdr` on `(compcode, itemcode, vendcode [as supcode])` to correlate quality results with the specific supplier's part number.
 
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