# Machine Relationships - Usage Examples

**Date:** 2025-11-06
**Purpose:** Show real-world examples of how machine relationships work

---

## Example Scenario: Dualpath Lathes with Shared Controller

**Setup:**
- Machine 2001 (CNC Lathe)
- Machine 2002 (CNC Lathe)
- PC 500 (Shopfloor PC, hostname: PC-CNC-01)

**Relationships:**
1. 2001 and 2002 share the same controller (dualpath)
2. Both machines communicate directly with PC 500

---

## Data Setup

### Step 1: Insert Relationship Types (one-time setup)
```sql
INSERT INTO relationshiptypes (relationshiptype, description, isbidirectional) VALUES
('Dualpath', 'Machines share same controller', 1),
('Controlled By', 'Machine controlled by PC/controller', 0),
('Controls', 'PC/controller controls machine', 0);
```

### Step 2: Link the dualpath machines
```sql
-- 2001 and 2002 are dualpath
INSERT INTO machinerelationships (relationshiptypeid, machineid1, machineid2, notes) VALUES
(1, 2001, 2002, 'Dualpath lathe pair - share controller');
```

### Step 3: Link machines to controlling PC
```sql
-- 2001 is controlled by PC 500
INSERT INTO machinerelationships (relationshiptypeid, machineid1, machineid2, notes) VALUES
(2, 2001, 500, 'Primary CNC controller');

-- 2002 is controlled by PC 500
INSERT INTO machinerelationships (relationshiptypeid, machineid1, machineid2, notes) VALUES
(2, 2002, 500, 'Primary CNC controller');
```

---

## Common Queries

### Q1: Is machine 2001 dualpath? With what machine?

```sql
SELECT
    m.machinenumber AS this_machine,
    CASE
        WHEN m2.machineid IS NOT NULL THEN 'Yes'
        ELSE 'No'
    END AS is_dualpath,
    m2.machinenumber AS dualpath_partner,
    rt.relationshiptype
FROM machines m
LEFT JOIN machinerelationships mr ON (
    (mr.machineid1 = m.machineid OR mr.machineid2 = m.machineid)
    AND mr.relationshiptypeid = 1
)
LEFT JOIN machines m2 ON (
    CASE
        WHEN mr.machineid1 = m.machineid THEN mr.machineid2
        ELSE mr.machineid1
    END = m2.machineid
)
LEFT JOIN relationshiptypes rt ON mr.relationshiptypeid = rt.relationshiptypeid
WHERE m.machineid = 2001;
```

**Result:**
```
this_machine | is_dualpath | dualpath_partner | relationshiptype
2001         | Yes         | 2002            | Dualpath
```

---

### Q2: Which PC controls machine 2001?

```sql
SELECT
    m.machinenumber AS cnc_machine,
    pc.machineid AS controller_id,
    pc.machinenumber AS controller_location,
    pc.hostname AS controller_hostname,
    rt.relationshiptype
FROM machines m
JOIN machinerelationships mr ON mr.machineid1 = m.machineid
JOIN machines pc ON mr.machineid2 = pc.machineid
JOIN relationshiptypes rt ON mr.relationshiptypeid = rt.relationshiptypeid
WHERE m.machineid = 2001
  AND mr.relationshiptypeid = 2;
```

**Result:**
```
cnc_machine | controller_id | controller_location | controller_hostname | relationshiptype
2001        | 500          | IT-LAB-01          | PC-CNC-01          | Controlled By
```

---

### Q3: What machines does PC 500 control?

```sql
SELECT
    pc.hostname AS controller,
    m.machinenumber AS controlled_machine,
    mt.machinetype,
    mr.notes
FROM machines pc
JOIN machinerelationships mr ON mr.machineid2 = pc.machineid
JOIN machines m ON mr.machineid1 = m.machineid
JOIN machinetypes mt ON m.machinetypeid = mt.machinetypeid
WHERE pc.machineid = 500
  AND mr.relationshiptypeid = 2
ORDER BY m.machinenumber;
```

**Result:**
```
controller | controlled_machine | machinetype | notes
PC-CNC-01  | 2001              | CNC - Lathe | Primary CNC controller
PC-CNC-01  | 2002              | CNC - Lathe | Primary CNC controller
```

---

### Q4: Complete picture - Machine + Dualpath + Controller + IP

```sql
SELECT
    m.machinenumber AS machine,
    mt.machinetype,

    -- Dualpath info
    m_dual.machinenumber AS dualpath_partner,

    -- Controller info
    pc.hostname AS controller,
    pc.machinenumber AS controller_location,

    -- Controller's IP
    c.address AS controller_ip

FROM machines m
JOIN machinetypes mt ON m.machinetypeid = mt.machinetypeid

-- Find dualpath partner
LEFT JOIN machinerelationships mr_dual ON (
    (mr_dual.machineid1 = m.machineid OR mr_dual.machineid2 = m.machineid)
    AND mr_dual.relationshiptypeid = 1
)
LEFT JOIN machines m_dual ON (
    CASE
        WHEN mr_dual.machineid1 = m.machineid THEN mr_dual.machineid2
        ELSE mr_dual.machineid1
    END = m_dual.machineid
)

-- Find controller
LEFT JOIN machinerelationships mr_ctrl ON (
    mr_ctrl.machineid1 = m.machineid
    AND mr_ctrl.relationshiptypeid = 2
)
LEFT JOIN machines pc ON mr_ctrl.machineid2 = pc.machineid

-- Get controller's IP address
LEFT JOIN communications c ON (
    pc.machineid = c.machineid
    AND c.comstypeid = 1  -- IP type
)

WHERE m.machineid IN (2001, 2002);
```

**Result:**
```
machine | machinetype | dualpath_partner | controller | controller_location | controller_ip
2001    | CNC - Lathe | 2002            | PC-CNC-01  | IT-LAB-01          | 192.168.1.50
2002    | CNC - Lathe | 2001            | PC-CNC-01  | IT-LAB-01          | 192.168.1.50
```

---

## Recommended View: vw_machine_relationships

Create a view for easy access:

```sql
CREATE VIEW vw_machine_relationships AS
SELECT
    m.machineid,
    m.machinenumber,
    m.alias,
    mt.machinetype,

    -- Dualpath info
    CASE WHEN m_dual.machineid IS NOT NULL THEN 1 ELSE 0 END AS is_dualpath,
    m_dual.machineid AS dualpath_partner_id,
    m_dual.machinenumber AS dualpath_partner,

    -- Controller info
    pc.machineid AS controller_id,
    pc.hostname AS controller_hostname,
    pc.machinenumber AS controller_location,

    -- Controller IP
    c.address AS controller_ip,

    -- Relationship counts
    (SELECT COUNT(*)
     FROM machinerelationships mr
     WHERE mr.machineid1 = m.machineid OR mr.machineid2 = m.machineid
    ) AS total_relationships

FROM machines m
JOIN machinetypes mt ON m.machinetypeid = mt.machinetypeid

-- Dualpath partner
LEFT JOIN machinerelationships mr_dual ON (
    (mr_dual.machineid1 = m.machineid OR mr_dual.machineid2 = m.machineid)
    AND mr_dual.relationshiptypeid = 1
    AND mr_dual.isactive = 1
)
LEFT JOIN machines m_dual ON (
    CASE
        WHEN mr_dual.machineid1 = m.machineid THEN mr_dual.machineid2
        ELSE mr_dual.machineid1
    END = m_dual.machineid
)

-- Controller PC
LEFT JOIN machinerelationships mr_ctrl ON (
    mr_ctrl.machineid1 = m.machineid
    AND mr_ctrl.relationshiptypeid = 2
    AND mr_ctrl.isactive = 1
)
LEFT JOIN machines pc ON mr_ctrl.machineid2 = pc.machineid

-- Controller IP
LEFT JOIN communications c ON (
    pc.machineid = c.machineid
    AND c.comstypeid = 1
)

WHERE m.isactive = 1;
```

### Using the View:

```sql
-- Simple query for machine 2001
SELECT * FROM vw_machine_relationships WHERE machineid = 2001;

-- Show all dualpath machines
SELECT * FROM vw_machine_relationships WHERE is_dualpath = 1;

-- Show all machines controlled by PC 500
SELECT * FROM vw_machine_relationships WHERE controller_id = 500;
```

---

## ASP Code Examples

### Check if machine is dualpath:
```vbscript
strSQL = "SELECT * FROM vw_machine_relationships WHERE machineid = ?"
Set rs = ExecuteParameterizedQuery(objConn, strSQL, Array(CLng(machineId)))

If Not rs.EOF Then
    isDualpath = rs("is_dualpath")

    If isDualpath = 1 Then
        Response.Write("Dualpath with: " & rs("dualpath_partner"))
    End If

    If Not IsNull(rs("controller_hostname")) Then
        Response.Write("Controller: " & rs("controller_hostname"))
        Response.Write(" (IP: " & rs("controller_ip") & ")")
    End If
End If
```

### Display machine card with relationships:
```vbscript
<div class="machine-card">
    <h3>Machine <%= rs("machinenumber") %></h3>
    <p>Type: <%= rs("machinetype") %></p>

    <% If rs("is_dualpath") = 1 Then %>
        <div class="dualpath-badge">
            <strong>Dualpath:</strong> Linked with <%= rs("dualpath_partner") %>
        </div>
    <% End If %>

    <% If Not IsNull(rs("controller_hostname")) Then %>
        <div class="controller-info">
            <strong>Controller:</strong> <%= rs("controller_hostname") %><br>
            <strong>Location:</strong> <%= rs("controller_location") %><br>
            <strong>IP:</strong> <%= rs("controller_ip") %>
        </div>
    <% End If %>
</div>
```

---

## Benefits of This Design

✅ **Flexible** - Any machine can relate to any other machine
✅ **Bidirectional** - Dualpath works both ways automatically
✅ **Directional** - "Controlled By" has clear direction
✅ **Extensible** - Easy to add new relationship types
✅ **Query-friendly** - Simple JOINs to get related machines
✅ **Unified** - PCs are machines too, so PC-to-machine relationships use same table
✅ **Future-proof** - Supports clusters, backups, master-slave, etc.

---

## Future Relationship Types (Examples)

```sql
INSERT INTO relationshiptypes (relationshiptype, description, isbidirectional) VALUES
('Backup', 'Backup/redundant machine', 1),
('Cluster Member', 'Member of machine cluster', 1),
('Feeds Into', 'Output feeds into next machine', 0),
('Mirror', 'Mirrored configuration', 1),
('Hot Standby', 'Hot standby/failover machine', 0);
```

These would all work with the same `machinerelationships` table!
