How can I union all rows of two different tables using MySQL 8.0.17 version?

Hi,

These are two tables of my MySQL database 8.0.17

On these tables the corresponding column for each tables is the column tUnity

-- ------------------------------ Table structure for t_release-- ----------------------------DROPTABLEIFEXISTS`t_release`;CREATETABLE`t_release`  (`tID`int(11) NOTNULL AUTO_INCREMENT,`tUnity`varchar(255) DEFAULTNULL,`tMonthYear`varchar(255) DEFAULTNULL,`tHHrelease` datetime(0) DEFAULTNULL,`tHHapproved` datetime(0) DEFAULTNULL,
  PRIMARY KEY (`tID`) USING BTREE
) ENGINE = InnoDB;-- ------------------------------ Records of t_release-- ----------------------------INSERTINTO`t_release`VALUES (1, 'D41', '1-2021', '2021-02-26 16:22:19', NULL);-- ------------------------------ Table structure for t_unities-- ----------------------------DROPTABLEIFEXISTS`t_unities`;CREATETABLE`t_unities`  (`tID`int(11) NOTNULL AUTO_INCREMENT,`tUnity`varchar(255) DEFAULTNULL,
  PRIMARY KEY (`tID`) USING BTREE
) ENGINE = InnoDB;-- ------------------------------ Records of t_unities-- ----------------------------INSERTINTO`t_unities`VALUES (1, 'D40');INSERTINTO`t_unities`VALUES (2, 'D41');INSERTINTO`t_unities`VALUES (3, 'D42');INSERTINTO`t_unities`VALUES (4, 'D43');INSERTINTO`t_unities`VALUES (5, 'D44');INSERTINTO`t_unities`VALUES (6, 'D45');INSERTINTO`t_unities`VALUES (7, 'D46');INSERTINTO`t_unities`VALUES (8, 'D47');INSERTINTO`t_unities`VALUES (9, 'D48');INSERTINTO`t_unities`VALUES (10, 'D49');

I need union these tables for this return

+--------+------------+---------------------+-------------+--------+| qUnity | tMonthYear | tHHrelease          | tHHapproved | tUnity |+--------+------------+---------------------+-------------+--------+| D40    ||                     | NULL        | D40    || D41    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D42    ||                     | NULL        | D42    || D43    ||                     | NULL        | D43    || D44    ||                     | NULL        | D43    || D45    ||                     | NULL        | D45    || D46    ||                     | NULL        | D46    || D47    ||                     | NULL        | D47    || D48    ||                     | NULL        | D48    || D49    ||                     | NULL        | D49    |+--------+------------+---------------------+-------------+--------+10 rows in set (0.03 sec)

And I have tried this SQL query

SELECTDISTINCT
    q.tUnity AS qUnity,
    t.tMonthYear,
    t.tHHrelease,
    t.tHHapproved,
    t.tUnity AS tUnityFROM
    t_release tLEFTJOIN t_unities q ONLEFT ( t.tUnity, 2 ) = LEFT ( q.tUnity, 2 ) WHERELEFT ( t.tUnity, 2 ) = LEFT ( 'd400', 2 ) AND tMonthYear = '1-2021';

But the return from this SQL query is

+--------+------------+---------------------+-------------+--------+| qUnity | tMonthYear | tHHrelease          | tHHapproved | tUnity |+--------+------------+---------------------+-------------+--------+| D40    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D41    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D42    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D43    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D44    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D45    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D46    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D47    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D48    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    || D49    |1-2021| 2021-02-26 16:22:19 | NULL        | D41    |+--------+------------+---------------------+-------------+--------+10 rows in set (0.03 sec)

Help me to do it.