[#2817] allowed 0 as RelationOptions.MinSelect value

models/schema/schema_field.go

@@ -653,7 +653,7 @@ func (o RelationOptions) Validate() error {
 
 	return validation.ValidateStruct(&o,
 		validation.Field(&o.CollectionId, validation.Required),
-		validation.Field(&o.MinSelect, validation.NilOrNotEmpty, validation.Min(1)),
+		validation.Field(&o.MinSelect, validation.Min(0)),
 		validation.Field(&o.MaxSelect, validation.NilOrNotEmpty, validation.Min(minVal)),
 	)
 }

models/schema/schema_field_test.go

@@ -2112,6 +2112,22 @@ func TestRelationOptionsValidate(t *testing.T) {
 			},
 			[]string{"collectionId"},
 		},
+		{
+			"MinSelect < 0",
+			schema.RelationOptions{
+				CollectionId: "abc",
+				MinSelect:    types.Pointer(-1),
+			},
+			[]string{"minSelect"},
+		},
+		{
+			"MinSelect >= 0",
+			schema.RelationOptions{
+				CollectionId: "abc",
+				MinSelect:    types.Pointer(0),
+			},
+			[]string{},
+		},
 		{
 			"MaxSelect <= 0",
 			schema.RelationOptions{
@@ -2128,6 +2144,42 @@ func TestRelationOptionsValidate(t *testing.T) {
 			},
 			[]string{},
 		},
+		{
+			"MinSelect < MaxSelect",
+			schema.RelationOptions{
+				CollectionId: "abc",
+				MinSelect:    nil,
+				MaxSelect:    types.Pointer(1),
+			},
+			[]string{},
+		},
+		{
+			"MinSelect = MaxSelect (non-zero)",
+			schema.RelationOptions{
+				CollectionId: "abc",
+				MinSelect:    types.Pointer(1),
+				MaxSelect:    types.Pointer(1),
+			},
+			[]string{},
+		},
+		{
+			"MinSelect = MaxSelect (both zero)",
+			schema.RelationOptions{
+				CollectionId: "abc",
+				MinSelect:    types.Pointer(0),
+				MaxSelect:    types.Pointer(0),
+			},
+			[]string{"maxSelect"},
+		},
+		{
+			"MinSelect > MaxSelect",
+			schema.RelationOptions{
+				CollectionId: "abc",
+				MinSelect:    types.Pointer(2),
+				MaxSelect:    types.Pointer(1),
+			},
+			[]string{"maxSelect"},
+		},
 	}
 
 	checkFieldOptionsScenarios(t, scenarios)