Separate migrations

userapi/storage/postgres/deltas/2022110411000000_server_names.go

@@ -34,26 +34,6 @@ func UpServerNames(ctx context.Context, tx *sql.Tx, serverName gomatrixserverlib
 		if _, err := tx.ExecContext(ctx, q); err != nil {
 			return fmt.Errorf("add server name to %q error: %w", table, err)
 		}
-		q = fmt.Sprintf(
-			"UPDATE %s SET server_name = %s WHERE server_name = '';",
-			pq.QuoteIdentifier(table), pq.QuoteLiteral(string(serverName)),
-		)
-		if _, err := tx.ExecContext(ctx, q); err != nil {
-			return fmt.Errorf("write server names to %q error: %w", table, err)
-		}
-	}
-	return nil
-}
-
-func DownServerNames(ctx context.Context, tx *sql.Tx) error {
-	for _, table := range serverNamesTables {
-		q := fmt.Sprintf(
-			"ALTER TABLE IF EXISTS %s DELETE COLUMN server_name;",
-			pq.QuoteIdentifier(table),
-		)
-		if _, err := tx.ExecContext(ctx, q); err != nil {
-			return fmt.Errorf("remove server name from %q error: %w", table, err)
-		}
 	}
 	return nil
 }

userapi/storage/postgres/deltas/2022110411000001_server_names.go

@@ -0,0 +1,28 @@
+package deltas
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// I know what you're thinking: you're wondering "why doesn't this use $1
+// and pass variadic parameters to ExecContext?" — the answer is because
+// PostgreSQL doesn't expect the table name to be specified as a substituted
+// argument in that way so it results in a syntax error in the query.
+
+func UpServerNamesPopulate(ctx context.Context, tx *sql.Tx, serverName gomatrixserverlib.ServerName) error {
+	for _, table := range serverNamesTables {
+		q := fmt.Sprintf(
+			"UPDATE %s SET server_name = %s WHERE server_name = '';",
+			pq.QuoteIdentifier(table), pq.QuoteLiteral(string(serverName)),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("write server names to %q error: %w", table, err)
+		}
+	}
+	return nil
+}

userapi/storage/postgres/storage.go

@@ -45,6 +45,12 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 		Up:      deltas.UpRenameTables,
 		Down:    deltas.DownRenameTables,
 	})
+	m.AddMigrations(sqlutil.Migration{
+		Version: "userapi: server names",
+		Up: func(ctx context.Context, txn *sql.Tx) error {
+			return deltas.UpServerNames(ctx, txn, serverName)
+		},
+	})
 	if err = m.Up(base.Context()); err != nil {
 		return nil, err
 	}
@@ -100,11 +106,10 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 
 	m = sqlutil.NewMigrator(db)
 	m.AddMigrations(sqlutil.Migration{
-		Version: "userapi: server names",
+		Version: "userapi: server names populate",
 		Up: func(ctx context.Context, txn *sql.Tx) error {
-			return deltas.UpServerNames(ctx, txn, serverName)
+			return deltas.UpServerNamesPopulate(ctx, txn, serverName)
 		},
-		Down: deltas.DownServerNames,
 	})
 	if err = m.Up(base.Context()); err != nil {
 		return nil, err

userapi/storage/sqlite3/deltas/2022110411000000_server_names.go

@@ -42,26 +42,6 @@ func UpServerNames(ctx context.Context, tx *sql.Tx, serverName gomatrixserverlib
 		if _, err := tx.ExecContext(ctx, q); err != nil {
 			return fmt.Errorf("add server name to %q error: %w", table, err)
 		}
-		q = fmt.Sprintf(
-			"UPDATE %s SET server_name = %s WHERE server_name = '';",
-			pq.QuoteIdentifier(table), pq.QuoteLiteral(string(serverName)),
-		)
-		if _, err := tx.ExecContext(ctx, q); err != nil {
-			return fmt.Errorf("write server names to %q error: %w", table, err)
-		}
-	}
-	return nil
-}
-
-func DownServerNames(ctx context.Context, tx *sql.Tx) error {
-	for _, table := range serverNamesTables {
-		q := fmt.Sprintf(
-			"ALTER TABLE %s DELETE COLUMN server_name;",
-			pq.QuoteIdentifier(table),
-		)
-		if _, err := tx.ExecContext(ctx, q); err != nil {
-			return fmt.Errorf("remove server name from %q error: %w", table, err)
-		}
 	}
 	return nil
 }

userapi/storage/sqlite3/deltas/2022110411000001_server_names.go

@@ -0,0 +1,36 @@
+package deltas
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// I know what you're thinking: you're wondering "why doesn't this use $1
+// and pass variadic parameters to ExecContext?" — the answer is because
+// PostgreSQL doesn't expect the table name to be specified as a substituted
+// argument in that way so it results in a syntax error in the query.
+
+func UpServerNamesPopulate(ctx context.Context, tx *sql.Tx, serverName gomatrixserverlib.ServerName) error {
+	for _, table := range serverNamesTables {
+		q := fmt.Sprintf(
+			"SELECT name FROM sqlite_schema WHERE type='table' AND name=%s;",
+			pq.QuoteIdentifier(table),
+		)
+		var c int
+		if err := tx.QueryRowContext(ctx, q).Scan(&c); err != nil || c == 0 {
+			continue
+		}
+		q = fmt.Sprintf(
+			"UPDATE %s SET server_name = %s WHERE server_name = '';",
+			pq.QuoteIdentifier(table), pq.QuoteLiteral(string(serverName)),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("write server names to %q error: %w", table, err)
+		}
+	}
+	return nil
+}

userapi/storage/sqlite3/storage.go

@@ -43,6 +43,12 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 		Up:      deltas.UpRenameTables,
 		Down:    deltas.DownRenameTables,
 	})
+	m.AddMigrations(sqlutil.Migration{
+		Version: "userapi: server names",
+		Up: func(ctx context.Context, txn *sql.Tx) error {
+			return deltas.UpServerNames(ctx, txn, serverName)
+		},
+	})
 	if err = m.Up(base.Context()); err != nil {
 		return nil, err
 	}
@@ -98,11 +104,10 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 
 	m = sqlutil.NewMigrator(db)
 	m.AddMigrations(sqlutil.Migration{
-		Version: "userapi: server names",
+		Version: "userapi: server names populate",
 		Up: func(ctx context.Context, txn *sql.Tx) error {
-			return deltas.UpServerNames(ctx, txn, serverName)
+			return deltas.UpServerNamesPopulate(ctx, txn, serverName)
 		},
-		Down: deltas.DownServerNames,
 	})
 	if err = m.Up(base.Context()); err != nil {
 		return nil, err