add unique constraints

service_a/internal/domains/meteo/domain.go

@@ -66,6 +66,7 @@ var (
 	ErrCannotParseFile            = errors.New("cannot parse file")
 	ErrValidateRecord             = errors.New("error validating record")
 	ErrRecordNotValid             = errors.New("record not valid")
+	ErrRecordAlreadyExists        = errors.New("record already exists")
 	ErrReadingCSVHeader           = errors.New("error reading CSV header")
 	ErrReadingCSVRow              = errors.New("error reading CSV row")
 	ErrMissingOrInvalidDate       = errors.New("missing or invalid date")

service_a/server/database/migrations/001_data.up.sql

@@ -11,7 +11,7 @@ create table public.ingest_batch
     id serial primary key,
 
     elapsed_ms int not null default 0,
-    file_checksum text not null,
+    file_checksum text not null unique,
 
     created_at timestamp not null default now()
 );
@@ -33,7 +33,9 @@ create table public.meteo_data
     rainfall numeric(5, 2) not null,
     cloudiness int not null,
 
-    created_at timestamp not null default now()
+    created_at timestamp not null default now(),
+
+    constraint uq_meteo_data_record unique (location_name_norm, date_of_register, max_temp, min_temp, rainfall, cloudiness)
 );
 
 create index idx_meteo_data_location_name_norm on public.meteo_data (location_name_norm);