pdiinspectiondtl

### 1) Overview
 The `pdiinspectiondtl` table stores the granular line-item results of Pre-Despatch Inspections (PDI). Each record represents a specific quality parameter (numeric or characteristic) checked against an item within a specific Inspection Report (`irno`). It captures multiple observations (OB1–OB10), tolerance limits (Upper/Lower), the instrument used, and the final pass/fail result for that specific parameter.
 
 ### 2) Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Primary Key | | PK |
 | **compcode** | string | No | Company Identifier | e.g., "DAS" | FK (Join to `company`) |
 | **irno** | integer | No | Inspection Report Number | | FK (Join to `pdiinspectionhdr`) |
 | **itemcode** | string | Yes | Internal Item Identifier | | FK (Join to `itemmas`) |
 | **paracode** | string | Yes | Quality Parameter Identifier | e.g., "L1", "HH" | FK (Join to `itemparamas.iparacode`) |
 | **instcode** | string | Yes | Instrument Code used for measurement | e.g., "001" (Vernier) | Likely Join to `icsgaugemaster.code` |
 | **leastcount** | number | Yes | Minimum measurement unit of the instrument | | Numeric analysis |
 | **OB1 - OB10** | string | Yes | Observation readings 1 through 10 | Numeric or "OK" | Data Entry / Validation |
 | **remarks** | string | Yes | General notes for the specific parameter check | | |
 | **result** | string | Yes | Final status of the parameter | "OK", "REJ" | Filtering non-conformance |
 | **specification** | string | Yes | Human-readable target range | e.g., "280.00 - 281.00 MM" | Report display |
 | **sno** | integer | Yes | Serial sequence within the report | | Order by |
 | **revno** | string | Yes | Revision number of the inspection standard | | Versioning |
 | **lotsize** | integer | Yes | Quantity of items in the lot being inspected | | Volumetric analysis |
 | **saleitemcode** | string | Yes | External/Customer-facing item code | | Join to `saleitemmas` |
 | **paratype** | string | Yes | Nature of the parameter | "N" (Numeric), "C" (Char) | Conditional logic |
 | **lwlimit** | string | Yes | Lower limit/Tolerance | | Validation |
 | **uplimit** | string | Yes | Upper limit/Tolerance | | Validation |
 | **deviationrem** | string | Yes | Remarks regarding deviations from spec | | Quality control notes |
 | **paraname** | string | Yes | Descriptive name of the parameter | | Report display |
 | **changeitemname**| string | Yes | Used if the item was substituted | | Tracking |
 | **Min_Reading** | string | Yes | Calculated minimum from observations | | Likely Aggregation |
 | **Max_Reading** | string | Yes | Calculated maximum from observations | | Likely Aggregation |
 
 ### 3) Relationships & Join Map
 
 #### Authoritative Joins (Verified via SCHEMA_MAP & REFERENCE_JSON)
 * **pdiinspectionhdr**: Join on `irno` and `compcode`. This connects detail lines to the report header (date, customer, invoice number).
 * **itemparamas**: Join `paracode` to `itemparamas.iparacode` and `compcode`. Used to retrieve parameter definitions and measurement types.
 * **invhdr**: Indirect join via `pdiinspectionhdr`. Link `pdiinspectionhdr.invno` to `invhdr.invno`.
 
 #### Logical Joins (Based on naming conventions)
 * **itemmas**: Join on `itemcode` and `compcode` for master item specifications.
 * **saleitemmas**: Join on `saleitemcode` and `compcode` for customer-specific part information.
 * **icsgaugemaster**: Join `instcode` to `icsgaugemaster.code` (or `codeno`) and `compcode` to identify the specific tool used for the check.