1 files changed, 47 insertions, 0 deletions
diff --git a/vendor/xorm.io/builder/builder_union.go b/vendor/xorm.io/builder/builder_union.go
new file mode 100644
index 0000000000..4ba9216178
--- /dev/null
+++ b/vendor/xorm.io/builder/builder_union.go
@@ -0,0 +1,47 @@
+// Copyright 2018 The Xorm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package builder
+
+import (
+	"fmt"
+	"strings"
+)
+
+func (b *Builder) unionWriteTo(w Writer) error {
+	if b.limitation != nil || b.cond.IsValid() ||
+		b.orderBy != "" || b.having != "" || b.groupBy != "" {
+		return ErrNotUnexpectedUnionConditions
+	}
+
+	for idx, u := range b.unions {
+		current := u.builder
+		if current.optype != selectType {
+			return ErrUnsupportedUnionMembers
+		}
+
+		if len(b.unions) == 1 {
+			if err := current.selectWriteTo(w); err != nil {
+				return err
+			}
+		} else {
+			if b.dialect != "" && b.dialect != current.dialect {
+				return ErrInconsistentDialect
+			}
+
+			if idx != 0 {
+				fmt.Fprint(w, fmt.Sprintf(" UNION %v ", strings.ToUpper(u.unionType)))
+			}
+			fmt.Fprint(w, "(")
+
+			if err := current.selectWriteTo(w); err != nil {
+				return err
+			}
+
+			fmt.Fprint(w, ")")
+		}
+	}
+
+	return nil
+}