Question

I have two tables:

Table_A
name1
create_date

Table_B
name2
keep_time

name1 is something like xxxxxx-yyy and name2 is like xxxxxxx. name2 is exactly the first part of the name1 separated by ‘-‘.

I would like to get all the rows in Table_A, whose keep_time is less than (now – create_date).

As you understand, the problem is how I can split the name1 by ‘-‘ character and get the first part and get the keep_time from Table_B by corresponding name2.

I need to write SQL in MySQL for such query?

Thanks

Answer 1

If I’ve understood your requirements correctly:

SELECT a.* FROM table_A a
  LEFT JOIN table_B b on b.name2 = SUBSTRING_INDEX(a.name1, '-', 1)
  WHERE DATEDIFF(NOW(), a.create_date) < b.keep_time  

EDIT : DateDiff.