dialect/sql: improve support for subqueries (#3274)

dialect/sql/builder.go

@@ -2367,7 +2367,25 @@ func (s *Selector) Table() *SelectTable {
 	if len(s.from) == 0 {
 		return nil
 	}
-	return s.from[0].(*SelectTable)
+	return selectTable(s.from[0])
+}
+
+// selectTable returns a *SelectTable from the given TableView.
+func selectTable(tb TableView) *SelectTable {
+	if tb == nil {
+		return nil
+	}
+	switch view := tb.(type) {
+	case *SelectTable:
+		return view
+	case *Selector:
+		if len(view.from) == 0 {
+			return nil
+		}
+		return selectTable(view.from[0])
+	default:
+		panic(fmt.Sprintf("unhandled TableView type %T", tb))
+	}
 }
 
 // TableName returns the name of the selected table or alias of selector.

dialect/sql/builder_test.go

@@ -2355,3 +2355,14 @@ func TestMultipleFrom(t *testing.T) {
 	require.Equal(t, []any{"neutrino|(dark & matter)", 10}, args)
 	require.Equal(t, `SELECT items.*, ts_rank_cd(search, search_query) AS "rank" FROM "items", to_tsquery($1) AS search_query WHERE "value" = $2 AND search @@ search_query`, query)
 }
+
+func TestFormattedColumnFromSubQuery(t *testing.T) {
+	q := Select("*").From(Select("*").AppendSelectExprAs(P(func(b *Builder) {
+		b.SetDialect(dialect.Postgres)
+		b.WriteString("calculate_score")
+		b.Wrap(func(bb *Builder) {
+			bb.WriteString(Table("table_name").C("field_name")).Comma().Args("test")
+		})
+	}), "score").From(Table("table_name").As("table_name_alias")))
+	require.Equal(t, "`table_name_alias`.`score`", q.C("score"))
+}