mariadb 10.1.8-MariaDB-log (root) [test]> create table t1 (id serial, t time);
Query OK, 0 rows affected (0.01 sec)

mariadb 10.1.8-MariaDB-log (root) [test]> insert into t1 (t) values ('12:30:00');
Query OK, 1 row affected (0.00 sec)

mariadb 10.1.8-MariaDB-log (root) [test]> select * from t1 where t = '2000-01-01 12:30:00';
Empty set (0.00 sec)





mysql 5.6.26-log (root) [test]> create table t1 (id serial, t time);
Query OK, 0 rows affected (0.01 sec)

mysql 5.6.26-log (root) [test]> insert into t1 (t) values ('12:30:00');
Query OK, 1 row affected (0.00 sec)

mysql 5.6.26-log (root) [test]> select * from t1 where t = '2000-01-01 12:30:00';
+----+----------+
| id | t        |
+----+----------+
|  1 | 12:30:00 |
+----+----------+
1 row in set (0.00 sec)



postgresql=# create table t1 (id serial, t time);
CREATE TABLE
postgresql=# insert into t1 (t) values ('12:30:00');
INSERT 0 1
postgresql=# select * from t1 where t = '2000-01-01 12:30:00';
    t
----------
 12:30:00
(1 row)



SQL Server

create table t1 (id int identity(1,1), t time);
insert into t1 (t) values ('12:30:00');
select * from t1 where t = '2000-01-01 12:30:00';
1	12:30:00.0000000