mariadb/mysql-test/t/count_distinct2.test

create table t1(n1 int, n2 int, s char(20), vs varchar(20), t text);
insert into t1 values (1,11, 'one','eleven', 'eleven'),
 (1,11, 'one','eleven', 'eleven'),
 (2,11, 'two','eleven', 'eleven'),
 (2,12, 'two','twevle', 'twelve'),
 (2,13, 'two','thirteen', 'foo'),
 (2,13, 'two','thirteen', 'foo'),
 (2,13, 'two','thirteen', 'bar'),
 (NULL,13, 'two','thirteen', 'bar'),
 (2,NULL, 'two','thirteen', 'bar'),
 (2,13, NULL,'thirteen', 'bar'),
 (2,13, 'two',NULL, 'bar'),
 (2,13, 'two','thirteen', NULL);

select distinct n1 from t1;
select count(distinct n1) from t1;

select distinct n2 from t1;
select count(distinct n2) from t1;

select distinct s from t1;
select count(distinct s) from t1;

select distinct vs from t1;
select count(distinct vs) from t1;

select distinct t from t1;
select count(distinct t) from t1;

select distinct n1,n2 from t1;
select count(distinct n1,n2) from t1;

select distinct n1,s from t1;
select count(distinct n1,s) from t1;

select distinct s,n1,vs from t1;
select count(distinct s,n1,vs) from t1;

select distinct s,t from t1;
select count(distinct s,t) from t1;

select count(distinct n1), count(distinct n2) from t1;