Fix SQL to drop fields

migrations/sqlite/2021-09-08-131154_instances_add_keys/down.sql

@@ -1,2 +1,30 @@
-ALTER TABLE instances DROP COLUMN private_key;
-ALTER TABLE instances DROP COLUMN public_key;
+CREATE TABLE instances_old (
+    id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+    public_domain VARCHAR NOT NULL,
+    name VARCHAR NOT NULL,
+    local BOOLEAN NOT NULL DEFAULT 'f',
+    blocked BOOLEAN NOT NULL DEFAULT 'f',
+    creation_date DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    open_registrations BOOLEAN NOT NULL DEFAULT 't',
+    short_description TEXT NOT NULL DEFAULT '',
+    long_description TEXT NOT NULL DEFAULT '',
+    default_license TEXT NOT NULL DEFAULT 'CC-0',
+    long_description_html VARCHAR NOT NULL DEFAULT '',
+    short_description_html VARCHAR NOT NULL DEFAULT ''
+)
+INSERT INTO instances_old SELECT
+    id,
+    public_domain,
+    name,
+    local,
+    blocked,
+    creation_date,
+    open_registrations,
+    short_description,
+    long_description,
+    default_license,
+    long_description_html,
+    short_description_html
+FROM instances;
+DROP TABLE instances;
+ALTER TABLE instances_old RENAME TO instances;