fix(server): remove NOT NULL constraint on branch (fixes #289)

src/db/db.v

@@ -17,11 +17,13 @@ const (
 		$embed_file('migrations/001-initial/up.sql'),
 		$embed_file('migrations/002-rename-to-targets/up.sql'),
 		$embed_file('migrations/003-target-url-type/up.sql'),
+		$embed_file('migrations/004-nullable-branch/up.sql')
 	]
 	migrations_down = [
 		$embed_file('migrations/001-initial/down.sql'),
 		$embed_file('migrations/002-rename-to-targets/down.sql'),
 		$embed_file('migrations/003-target-url-type/down.sql'),
+		$embed_file('migrations/004-nullable-branch/down.sql')
 	]
 )
 
@@ -60,7 +62,7 @@ pub fn init(db_path string) !VieterDb {
 			res := conn.exec_none(part)
 
 			if res != sqlite.sqlite_done {
-				return error('An error occurred while applying migration $version_num')
+				return error('An error occurred while applying migration $version_num: SQLite error code $res')
 			}
 		}
 

src/db/migrations/004-nullable-branch/down.sql

@@ -0,0 +1,26 @@
+-- This down won't really work because it'll throw NOT NULL errors, but I'm
+-- just putting it here for future reference (still not sure whether I'm even
+    -- gonna use these)
+PRAGMA foreign_keys=off;
+
+BEGIN TRANSACTION;
+
+ALTER TABLE Target RENAME TO _Target_old;
+
+CREATE TABLE Target (
+    id INTEGER PRIMARY KEY,
+    url TEXT NOT NULL,
+    branch TEXT NOT NULL,
+    repo TEXT NOT NULL,
+    schedule TEXT,
+    kind TEXT NOT NULL DEFAULT 'git'
+);
+
+INSERT INTO Target (id, url, branch, repo, schedule, kind)
+    SELECT id, url, branch, repo, schedule, kind FROM _Target_old;
+
+DROP TABLE _Target_old;
+
+COMMIT;
+
+PRAGMA foreign_keys=on;

src/db/migrations/004-nullable-branch/up.sql

@@ -0,0 +1,23 @@
+PRAGMA foreign_keys=off;
+
+BEGIN TRANSACTION;
+
+ALTER TABLE Target RENAME TO _Target_old;
+
+CREATE TABLE Target (
+    id INTEGER PRIMARY KEY,
+    url TEXT NOT NULL,
+    branch TEXT,
+    repo TEXT NOT NULL,
+    schedule TEXT,
+    kind TEXT NOT NULL DEFAULT 'git'
+);
+
+INSERT INTO Target (id, url, branch, repo, schedule, kind)
+    SELECT id, url, branch, repo, schedule, kind FROM _Target_old;
+
+DROP TABLE _Target_old;
+
+COMMIT;
+
+PRAGMA foreign_keys=on;