itemparamas

### 1. Overview
 The `itemparamas` (Item Parameter Master) table serves as the central repository for defining technical inspection characteristics and measurement parameters. It stores metadata for physical attributes such as diameters, angles, chamfers, and appearance checks. Each record defines the precision (least count), default tolerance, and classification (Numeric vs. Character) required for quality control and PDI (Pre-Despatch Inspection) processes.
 
 ### 2. Column Dictionary
 
 | Column | Type | Nullable | Meaning | Allowed Values | SQL Usage |
 | :--- | :--- | :--- | :--- | :--- | :--- |
 | **index** | integer | No | Internal primary identifier for the record. | | PK |
 | **compcode** | string | No | Unique identifier for the company/organization unit. | e.g., "DAS" | FK (Common Join) |
 | **iparacode** | string | No | Unique alphanumeric code representing a specific measurement parameter. | A, AF, CD1, CH1 | Join Key |
 | **iparaname** | string | Yes | The descriptive label of the parameter used in reports. | APPEARANCE, BODY DIA, ANGLE | Display |
 | **leastcount** | number | Yes | The smallest measurement increment detectable by the instrument used for this parameter. | e.g., 0.0, 0.01 | Calculation |
 | **iparatype** | string | Yes | Classification of the parameter type. | **N**: Numeric, **C**: Character/Attribute | Logic |
 | **username** | string | Yes | The system user who created or last modified the parameter definition. | admin, system | Audit |
 | **valuetype** | string | Yes | The data type category for the parameter value. | **D**: Dimension | Logic |
 | **tolerence** | number | Yes | The default allowable deviation from the nominal value for this parameter. | e.g., 0.2, 0.3 | Validation |
 | **ParameterType** | string | Yes | Usage classification of the parameter. | **I**: Inspection | Filtering |
 | **ParaGroupCode** | number | Yes | Reference code to a logical grouping of parameters. | | FK (Likely) |
 | **Para_Dia_Mech** | string | Yes | Internal mechanical classification code. | **D**: Diameter, **M**: Mechanical | Logic |
 
 ### 3. Relationships & Join Map
 
 #### Logical Primary Key
 * `compcode`, `iparacode` (Composite uniqueness across the organization).
 
 #### Strict Joins (Based on SCHEMA_MAP & REFERENCE_JSON)
 * **dbo.pdiinspectiondtl**: Join on `pdiinspectiondtl.paracode = itemparamas.iparacode` AND `pdiinspectiondtl.compcode = itemparamas.compcode`. (Used to retrieve parameter names for inspection reports).
 * **dbo.parameteragnstitem**: Join on `parameteragnstitem.paracode = itemparamas.iparacode` AND `parameteragnstitem.compcode = itemparamas.compcode`. (Used to link specific items to their required inspection parameters).
 * **dbo.RMParaIRGroup**: Join on `RMParaIRGroup.ParaGroupCode = itemparamas.ParaGroupCode`. (Used to categorize parameters into functional groups).
 
 #### Likely Joins (Inferred)
 * **dbo.company**: Join on `compcode`.