BUGFIX: fix duplicate space participants error, making participants in a space unique

persistence/schema.sql

@@ -142,6 +142,7 @@ create table space_participants(rowid integer primary key,
     user_id integer not null,
     space_id not null,
 
+    unique(user_id, space_id)
     foreign key(space_id) references spaces(id)
     -- No foreign key for users, since they may not be downloaded yet and I don't want to
     -- download every user who joins a space

persistence/space_queries.go

@@ -44,7 +44,7 @@ func (p Profile) SaveSpace(s scraper.Space) error {
 	}
 	if len(space_participants) > 0 {
 		_, err = p.DB.NamedExec(`
-			insert into space_participants (user_id, space_id) values (:user_id, :space_id)
+			insert or replace into space_participants (user_id, space_id) values (:user_id, :space_id)
 		`, space_participants)
 		if err != nil {
 			return fmt.Errorf("Error saving participants (space ID %q, participants: %#v):\n  %w", s.ID, space_participants, err)

persistence/versions.go

@@ -8,8 +8,6 @@ import (
 	"offline_twitter/terminal_utils"
 )
 
-const ENGINE_DATABASE_VERSION = 17
-
 type VersionMismatchError struct {
 	EngineVersion   int
 	DatabaseVersion int
@@ -23,10 +21,7 @@ Please upgrade this application to a newer version to use this profile.  Or down
 	)
 }
 
-/**
+// The Nth entry is the migration that moves you from version N to version N+1.
- * The Nth entry is the migration that moves you from version N to version N+1.
- * `len(MIGRATIONS)` should always equal `ENGINE_DATABASE_VERSION`.
- */
 var MIGRATIONS = []string{
 	`create table polls (rowid integer primary key,
     id integer unique not null check(typeof(id) = 'integer'),
@@ -98,12 +93,26 @@ var MIGRATIONS = []string{
 		);`,
 	`create index if not exists index_tweets_user_id on tweets (user_id);`,
 	`alter table tweets add column is_expandable bool not null default 0;`,
-}
+	`create table space_participants_uniq(rowid integer primary key,
+			user_id integer not null,
+			space_id not null,
 
-/**
+			unique(user_id, space_id)
- * This should only get called on a newly created Profile.
+			foreign key(space_id) references spaces(id)
- * Subsequent updates should change the number, not insert a new row.
+			-- No foreign key for users, since they may not be downloaded yet and I don't want to
- */
+			-- download every user who joins a space
+		);
+
+		insert or replace into space_participants_uniq(rowid, user_id, space_id) select rowid, user_id, space_id from space_participants;
+
+		drop table space_participants;
+		alter table space_participants_uniq rename to space_participants;
+		vacuum;`,
+}
+var ENGINE_DATABASE_VERSION = len(MIGRATIONS)
+
+// This should only get called on a newly created Profile.
+// Subsequent updates should change the number, not insert a new row.
 func InitializeDatabaseVersion(db *sql.DB) {
 	db.MustExec("insert into database_version (version_number) values (?)", ENGINE_DATABASE_VERSION)
 }
@@ -142,9 +151,7 @@ func (p Profile) check_and_update_version() error {
 	return nil
 }
 
-/**
+// Run all the migrations from version X to version Y, and update the `database_version` table's `version_number`
- * Run all the migrations from version X to version Y, and update the `database_version` table's `version_number`
- */
 func (p Profile) UpgradeFromXToY(x int, y int) error {
 	for i := x; i < y; i++ {
 		fmt.Printf(terminal_utils.COLOR_CYAN)