The used SELECT statements have a different number of columns

Question

For examples I don\'t know how many rows in each table are and I try to do like this:

SELECT * FROM members 
UNION 
SELECT * FROM inventory

Answer 1

Each SELECT statement within the MySQL UNION ALL operator must have the same number of fields in the result sets with similar data types Visit https://www.techonthenet.com/mysql/union_all.php