more tests for #14646

tests/queries/0_stateless/01475_mutation_with_if.reference

 1	150
+2020-02-28	car
+2020-03-28	dog
+2020-03-28	dog
+2020-08-02	car
+\N	cat
+2020-08-03	car
+2020-03-28	dog
+2020-08-02	car
+2020-03-28	dog
+2020-08-04	cat
+2020-08-04	car
+2020-08-04	car
+\N	cat
+2020-08-05	\N
+\N	car
+\N	dog
+\N	car

tests/queries/0_stateless/01475_mutation_with_if.sql

@@ -14,3 +14,42 @@ ALTER TABLE mutation_table UPDATE price = 150 WHERE id = 1 SETTINGS mutations_sy
 SELECT * FROM mutation_table;
 
 DROP TABLE IF EXISTS mutation_table;
+
+
+create table mutation_table (  dt Nullable(Date), name Nullable(String))
+engine MergeTree order by tuple();
+
+insert into mutation_table (name, dt) values ('car', '2020-02-28');
+insert into mutation_table (name, dt) values ('dog', '2020-03-28');
+
+select * from mutation_table;
+
+alter table mutation_table update dt = toDateOrNull('2020-08-02')
+where name = 'car' SETTINGS mutations_sync = 2;
+
+select * from mutation_table;
+
+insert into mutation_table (name, dt) values ('car', Null);
+insert into mutation_table (name, dt) values ('cat', Null);
+
+alter table mutation_table update dt = toDateOrNull('2020-08-03')
+where name = 'car' and dt is null SETTINGS mutations_sync = 2;
+
+select * from mutation_table;
+
+alter table mutation_table update dt = toDateOrNull('2020-08-04')
+where name = 'car' or dt is null SETTINGS mutations_sync = 2;
+
+select * from mutation_table;
+
+insert into mutation_table (name, dt) values (Null, '2020-08-05');
+
+alter table mutation_table update dt = Null
+where name is not null SETTINGS mutations_sync = 2;
+
+select * from mutation_table;
+
+
+DROP TABLE IF EXISTS mutation_table;
+
+