The SEDRIS Data Representation Model
APPENDIX B - Constraints
Table Property Description Constraints

Definition

For a <Table Property Description> instance P, the following conditions shall hold.

  1. The value_type of P and those of the corresponding elements of any applicable <Data Table> instances shall be consistent with the restrictions imposed by the meaning of P.

  2. If P specifies a real-valued EA or real-valued SE_Variable_Code M as its meaning, the value_unit of P shall specify a unit belonging to the EQ to which M is bound.

  3. If P does not specify a real-valued EA or real-valued SE_Variable_Code as its meaning, the value_unit and value_scale of P shall be set to EUC_UNITLESS and ESC_UNI, respectively.

Rationale

The data type and unit of measurement shall be semantically valid for the meaning of the <Property> instance.

Example

  1. Consider a <Property Value> instance P specifying a numeric meaning, (in this example, EAC_WIDTH). To be semantically valid, the attribute_value_type of the value field of P shall be compatible with the abstract value type bound to EAC_WIDTH (REAL), and the value shall be a member of EQC_LENGTH.

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Last updated: July 26, 2006 Copyright © 2006 SEDRIS