1// Copyright (c) 2012-present The upper.io/db authors. All rights reserved.
2//
3// Permission is hereby granted, free of charge, to any person obtaining
4// a copy of this software and associated documentation files (the
5// "Software"), to deal in the Software without restriction, including
6// without limitation the rights to use, copy, modify, merge, publish,
7// distribute, sublicense, and/or sell copies of the Software, and to
8// permit persons to whom the Software is furnished to do so, subject to
9// the following conditions:
10//
11// The above copyright notice and this permission notice shall be
12// included in all copies or substantial portions of the Software.
13//
14// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
18// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
19// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
20// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21
22package db
23
24// Union represents a compound joined by OR.
25type Union struct {
26	*compound
27}
28
29// Or adds more terms to the compound.
30func (o *Union) Or(orConds ...Compound) *Union {
31	var fn func(*[]Compound) error
32	if len(orConds) > 0 {
33		fn = func(in *[]Compound) error {
34			*in = append(*in, orConds...)
35			return nil
36		}
37	}
38	return &Union{o.compound.frame(fn)}
39}
40
41// Operator returns the OR operator.
42func (o *Union) Operator() CompoundOperator {
43	return OperatorOr
44}
45
46// Empty returns false if this struct holds no conditions.
47func (o *Union) Empty() bool {
48	return o.compound.Empty()
49}
50
51// Or joins conditions under logical disjunction. Conditions can be represented
52// by db.Cond{}, db.Or() or db.And().
53//
54// Example:
55//
56//	// year = 2012 OR year = 1987
57//	db.Or(
58//		db.Cond{"year": 2012},
59//		db.Cond{"year": 1987},
60//	)
61func Or(conds ...Compound) *Union {
62	return &Union{newCompound(defaultJoin(conds...)...)}
63}
64