# experiment_dclass

## Purpose

The **experiment_dclass** table defines the relationship between experiments and D-Class personnel.

It is used to track which D-Class participated in a given experiment.

This table represents the human test subject participation layer of experimental operations.

## Columns

| Field  | Type      | Description
|--------|-----------|----------------------------------------------------------------------------|
| id_exp | BIGINT    | Experiment identifier (part of composite PK, references experiment.id_exp)
| id_d   | MEDIUMINT | D-Class identifier (part of composite PK, references dclass.id_d)
|-------------------------------------------------------------------------------------------------|

## Relationships

- References **experiment.id_exp** through **id_exp** to assign D-Class personnel to a specific experiment.
- References **dclass.id_d** through **id_d** to link D-Class personnel as test subjects within experiments.


## Rules

- Each record links one experiment to one D-Class subject.
- The combination of **id_exp + id_d** uniquely identifies participation.
- A D-Class may participate in multiple experiments over time.
- Each experiment may involve multiple D-Class subjects.
- D-Class assignments are immutable once the experiment is completed.


## Example output

+--------+------+
| id_exp | id_d |
+--------+------+
|      5 |   10 |
|      5 |   20 |
+--------+------+