jobpohdramnd

### 1. Overview
 The `jobpohdramnd` table serves as the **Job Purchase Order Amendment Header**. It is a historical and version-tracking repository that stores the header-level details of modifications made to Job Purchase Orders. Every time a Purchase Order (PO) is amended, a new record is created with an incremented `amendno`.
 
 This table captures high-level changes such as updated terms and conditions, revised quotation references, effective dates (`wefdate`), and the specific `reason` for the amendment. It acts as the parent table for `jobpodtlamnd`, which contains the specific line-item changes for each amendment version.
 
 ### 2. Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Primary Key (Internal row identifier) | | Primary Key |
 | **compcode** | string | No | Company Identifier | e.g., "DAS" | Join Key |
 | **pono** | integer | No | Purchase Order Number | | Join Key |
 | **amendno** | integer | No | Amendment Version Number | 0 (Original), 1, 2... | Join Key / Versioning |
 | **podate** | datetime | No | Original Purchase Order Date | | Filtering |
 | **quotno** | string | Yes | Vendor Quotation Reference Number | | Reference |
 | **quotdate** | datetime | Yes | Date of the Vendor Quotation | | Reference |
 | **vendcode** | string | No | Primary Vendor Code | e.g., "YYU", "SIP" | Join Key (Vendor) |
 | **amenddate** | datetime | No | Date the amendment was recorded | | Audit/Tracking |
 | **term_1** | string | Yes | Payment/Commercial Term Clause 1 | | Documentation |
 | **term_2** | string | Yes | Delivery/Schedule Term Clause 2 | | Documentation |
 | **term_3** | string | Yes | Statutory/Tax Term Clause 3 | | Documentation |
 | **term_4** | string | Yes | Miscellaneous Term Clause 4 | | Documentation |
 | **authflag** | integer | No | Authorization Status | 1 = Authorized, 0 = Pending | Status Flag |
 | **wefdate** | datetime | Yes | "With Effect From" Date | | Logic/Effective Date |
 | **reason** | string | Yes | Justification for the PO amendment | | Audit |
 | **povalue** | decimal/string| Yes | Total value of the PO at this amendment | | Financials |
 | **povalueword**| string | Yes | PO Value expressed in words | | Printing/Reports |
 | **invyear** | integer | No | Financial/Accounting Year | e.g., 2013, 2021 | Join Key |
 | **vendcodeC** | string | Yes | Consignee or Secondary Vendor Code | | Likely Join Key |
 | **PODoc** | string | Yes | Physical or Digital Document Reference | | Reference |
 
 ### 3. Relationships & Join Map
 
 #### Parent Table (Logical)
 * **jobpohdr**: The original PO header table. Records in `jobpohdramnd` represent versions of the records found in `jobpohdr`.
 
 #### Child Tables (Physical Joins)
 * **jobpodtlamnd**: Join on `compcode`, `pono`, `amendno`, and `invyear`. This retrieves the amended line items (items, rates, quantities) associated with a specific header amendment.
 
 #### Reference Tables
 * **vendmas**: Join on `compcode` and `vendcode` to retrieve vendor contact and registration details.
 * **financialyear**: Join on `compcode` and `invyear` to determine accounting periods.
 
 #### JOIN STRICT Rules Applied:
 1. **To Detail Table**:
  ```sql
  SELECT * FROM dbo.jobpohdramnd H
  INNER JOIN dbo.jobpodtlamnd D 
  ON H.compcode = D.compcode 
  AND H.pono = D.pono 
  AND H.amendno = D.amendno 
  AND H.invyear = D.invyear
  ```
 2. **To Vendor Master**:
  ```sql
  SELECT * FROM dbo.jobpohdramnd H
  INNER JOIN dbo.vendmas V 
  ON H.compcode = V.compcode 
  AND H.vendcode = V.vendcode
  ```