i have a table called my_table like this
+------------+--------+--------+
| product | type_1 | type_2 |
+------------+--------+--------+
| Banana | A1 | B1 |
| Banana | B1 | B2 |
| Watermelon | A | B3 |
| Orange | B | B4 |
+------------+--------+--------+
so i want to make query IF the product banana, then it returns type_2, and the other product return type_1
so the expected results is just like this
+------------+------+
| product | type |
+------------+------+
| Banana | B1 |
| Banana | B2 |
| Watermelon | A |
| Orange | B |
+------------+------+
You can use CASE to select the column you want.
SELECT product, (CASE produt
WHEN 'Banana' THEN type_2
ELSE type_1
END) as type
FROM my_table