db: rework schema and infrastructure

migrations/1_down.sql

@@ -0,0 +1,6 @@
+-- DROP VIEW tagged_media_view;
+DROP VIEW tag_count_view;
+DROP TABLE media_tags;
+DROP TABLE tags;
+DROP TABLE media_content;
+DROP TABLE media;

migrations/1_up.sql

@@ -0,0 +1,35 @@
+CREATE TABLE media(
+	media_id INTEGER PRIMARY KEY,
+	seaweedfs_fid TEXT (33) NOT NULL,
+	filename TEXT (256) NOT NULL,
+	content_type TEXT (256)
+);
+
+CREATE TABLE tags(
+	tag_id INTEGER PRIMARY KEY,
+	name TEXT (256) NOT NULL UNIQUE
+);
+
+CREATE TABLE media_tags(
+	media_id INTEGER NOT NULL,
+	tag_id INTEGER NOT NULL,
+	FOREIGN KEY (media_id) REFERENCES media (media_id) ON DELETE CASCADE,
+	FOREIGN KEY (tag_id) REFERENCES tags (tag_id) ON DELETE CASCADE,
+	PRIMARY KEY(media_id, tag_id)
+);
+
+CREATE VIEW tag_count_view AS SELECT
+	tags.tag_id AS tag_id,
+	tags.name AS name,
+	COUNT(media_tags.media_id) AS count
+FROM tags
+	INNER JOIN media_tags USING (tag_id)
+	GROUP BY tag_id;
+
+-- CREATE VIEW tagged_media_view AS SELECT
+-- 	tags.tag_id AS tag_id,
+-- 	tags.name AS tag_name,
+-- 	media.media_id AS media_id
+-- FROM media
+-- 	INNER JOIN media_tags USING (media_id)
+-- 	INNER JOIN tags USING (tag_id);