Geojson DATA Operation change to Stable - Daniel C No.7

src/main/resources/db/migration/V7__Fix_Geometry_Column_Type.sql

@@ -4,11 +4,25 @@
 -- 1. First ensure PostGIS is enabled
 CREATE EXTENSION IF NOT EXISTS postgis;
 
--- 2. Clear existing data since it's in incorrect format (JTS serialized objects)
--- This data needs to be reprocessed anyway with the correct PostGIS approach
-DELETE FROM public.tb_map_sheet_learn_data_geom;
+-- 2. Check if column needs to be recreated (only if it's bytea type)
+-- Only clear data if the column type is incorrect and needs conversion
+DO $$
+BEGIN
+    -- Only delete data if geom column exists and is bytea type
+    IF EXISTS (
+        SELECT 1 FROM information_schema.columns 
+        WHERE table_name = 'tb_map_sheet_learn_data_geom' 
+        AND column_name = 'geom' 
+        AND data_type = 'bytea'
+    ) THEN
+        DELETE FROM public.tb_map_sheet_learn_data_geom WHERE geom IS NOT NULL;
+        RAISE NOTICE 'Cleared incorrect bytea geometry data for conversion';
+    ELSE
+        RAISE NOTICE 'Geometry column is already correct type, skipping data deletion';
+    END IF;
+END $$;
 
--- 3. Drop and recreate the geom column with correct PostGIS geometry type
+-- 3. Drop and recreate the geom column with correct PostGIS geometry type (only if needed)
 ALTER TABLE public.tb_map_sheet_learn_data_geom DROP COLUMN IF EXISTS geom;
 ALTER TABLE public.tb_map_sheet_learn_data_geom ADD COLUMN geom geometry(Polygon, 5186);