Add genre tables, read multiple-genres from tags

db/migration/20210715151153_add_genre_tables.go

@@ -0,0 +1,64 @@
+package migrations
+
+import (
+	"database/sql"
+
+	"github.com/pressly/goose"
+)
+
+func init() {
+	goose.AddMigration(upAddGenreTables, downAddGenreTables)
+}
+
+func upAddGenreTables(tx *sql.Tx) error {
+	_, err := tx.Exec(`
+create table if not exists genre
+(
+  id varchar not null primary key,
+  name varchar not null,  
+	constraint genre_name_ux
+		unique (name)
+);
+
+create table if not exists  album_genres
+(
+	album_id varchar default null not null
+		references album
+			on delete cascade,
+	genre_id varchar default null not null
+		references genre
+			on delete cascade,
+	constraint album_genre_ux
+		unique (album_id, genre_id)
+);
+
+create table if not exists  media_file_genres
+(
+	media_file_id varchar default null not null
+		references media_file
+			on delete cascade,
+	genre_id varchar default null not null
+		references genre
+			on delete cascade,
+	constraint media_file_genre_ux
+		unique (media_file_id, genre_id)
+);
+
+create table if not exists  artist_genres
+(
+	artist_id varchar default null not null
+		references artist
+			on delete cascade,
+	genre_id varchar default null not null
+		references genre
+			on delete cascade,
+	constraint artist_genre_ux
+		unique (artist_id, genre_id)
+);
+`)
+	return err
+}
+
+func downAddGenreTables(tx *sql.Tx) error {
+	return nil
+}