migrate database

internal/db/migrator/migrator.go

@@ -29,11 +29,31 @@ func dbType() string {
 	return "PostgreSQL"
 }
 
+const (
+	dialectSqlite   = "sqlite3"
+	dialectPostgres = "postgres"
+	cascadeSuffix   = " CASCADE"
+)
+
 func gooseDialect() string {
 	if !config.Config.Database.Enabled {
-		return "sqlite3"
+		return dialectSqlite
 	}
-	return "postgres"
+	return dialectPostgres
+}
+
+func tableExistsSQL(dialect string) string {
+	if dialect == dialectSqlite {
+		return "SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name=?"
+	}
+	return "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'public' AND table_name = $1"
+}
+
+func tablesWithPrefixSQL(dialect string) string {
+	if dialect == dialectSqlite {
+		return "SELECT name FROM sqlite_master WHERE type='table' AND name LIKE ?"
+	}
+	return "SELECT table_name FROM information_schema.tables WHERE table_schema='public' AND table_name LIKE $1"
 }
 
 func migrationDir() string {