invoices: add TODO to change the return type of the query

sqldb/sqlc/invoices.sql.go

@@ -547,6 +547,8 @@ INNER JOIN amp_sub_invoices a
 ON i.id = a.invoice_id AND a.set_id = $1
 `
 
+// TODO(ziggie): This query can only return one invoice if the set_id is
+// the primary key of amp_sub_invoices table.
 func (q *Queries) GetInvoiceBySetID(ctx context.Context, setID []byte) ([]Invoice, error) {
 	rows, err := q.db.QueryContext(ctx, getInvoiceBySetID, setID)
 	if err != nil {

sqldb/sqlc/querier.go

@@ -113,6 +113,8 @@ type Querier interface {
 	GetInvoice(ctx context.Context, arg GetInvoiceParams) ([]Invoice, error)
 	GetInvoiceByAddr(ctx context.Context, paymentAddr []byte) (Invoice, error)
 	GetInvoiceByHash(ctx context.Context, hash []byte) (Invoice, error)
+	// TODO(ziggie): This query can only return one invoice if the set_id is
+	// the primary key of amp_sub_invoices table.
 	GetInvoiceBySetID(ctx context.Context, setID []byte) ([]Invoice, error)
 	GetInvoiceFeatures(ctx context.Context, invoiceID int64) ([]InvoiceFeature, error)
 	GetInvoiceHTLCCustomRecords(ctx context.Context, invoiceID int64) ([]GetInvoiceHTLCCustomRecordsRow, error)

sqldb/sqlc/queries/invoices.sql

@@ -65,6 +65,8 @@ FROM invoices i
 WHERE i.payment_addr = $1;
 
 -- name: GetInvoiceBySetID :many
+-- TODO(ziggie): This query can only return one invoice if the set_id is 
+-- the primary key of amp_sub_invoices table.
 SELECT i.*
 FROM invoices i
 INNER JOIN amp_sub_invoices a