Fix

water-api/sql/add_meter_project_relation.sql

@@ -0,0 +1,68 @@
+-- ============================================================================
+-- Add project_id column to meters table
+-- This establishes the relationship between meters and projects
+-- ============================================================================
+
+-- Step 1: Add the column as nullable first (to allow existing data)
+ALTER TABLE meters 
+ADD COLUMN IF NOT EXISTS project_id UUID;
+
+-- Step 2: For existing meters without project_id, try to get it from their concentrator
+UPDATE meters m
+SET project_id = c.project_id
+FROM concentrators c
+WHERE m.concentrator_id = c.id
+  AND m.project_id IS NULL
+  AND m.concentrator_id IS NOT NULL;
+
+-- Step 3: Add foreign key constraint
+ALTER TABLE meters
+DROP CONSTRAINT IF EXISTS meters_project_id_fkey;
+
+ALTER TABLE meters 
+ADD CONSTRAINT meters_project_id_fkey 
+FOREIGN KEY (project_id) 
+REFERENCES projects(id) 
+ON DELETE CASCADE;
+
+-- Step 4: Create index for better query performance
+CREATE INDEX IF NOT EXISTS idx_meters_project_id ON meters(project_id);
+
+-- Step 5: Add comment for documentation
+COMMENT ON COLUMN meters.project_id IS 'Project to which this meter belongs';
+
+-- ============================================================================
+-- Verify the changes
+-- ============================================================================
+
+-- Check if the column was added
+SELECT 
+    column_name, 
+    data_type, 
+    is_nullable,
+    column_default
+FROM information_schema.columns 
+WHERE table_name = 'meters' 
+  AND column_name = 'project_id';
+
+-- Check the constraint
+SELECT
+    conname AS constraint_name,
+    contype AS constraint_type,
+    pg_get_constraintdef(oid) AS constraint_definition
+FROM pg_constraint
+WHERE conrelid = 'meters'::regclass
+  AND conname LIKE '%project_id%';
+
+-- Show meters with their project info
+SELECT 
+    m.id,
+    m.name,
+    m.serial_number,
+    m.project_id,
+    p.name AS project_name,
+    c.name AS concentrator_name
+FROM meters m
+LEFT JOIN projects p ON m.project_id = p.id
+LEFT JOIN concentrators c ON m.concentrator_id = c.id
+LIMIT 10;