statement ok
create table t1(id int primary key, v1 int unique)

statement ok
insert into t1 values (1,1), (2,2), (3,3), (4,4)

statement ok
alter table t1 add column v2 int null

statement ok
alter table t1 add column if not exists v3 int default 0

statement ok
alter table t1 add column if not exists v3 int default 0

statement error
alter table t1 add column v4 int

query IIII rowsort
select * from t1
----
1 1 null 0
2 2 null 0
3 3 null 0
4 4 null 0

statement ok
alter table t1 drop column if exists v1

statement ok
alter table t1 drop column if exists v1

statement error
alter table t1 drop column id

query IIII rowsort
select * from t1
----
1 null 0
2 null 0
3 null 0
4 null 0

statement ok
create table t2(id int primary key, v1 int)

statement ok
insert into t2 values (1,1)

statement error
alter table t2 add column v2 int default 0 unique

query IIII rowsort
select * from t2
----
1 1 0

statement ok
drop table t1