Question

I use the query

Select t1.name as first, t2.name as second From products t1, products t2

that creates two columns like below. (A,B are for explaining purposes)

Before the query

-name-
A
B
C
D
E

After the query

-first- -second-
A        A
B        A
C        A
D        A
E        A
A        B
B        B
C        B
D        B
E        B

How to check if a row of the first column is similar to the second ?

UPDATE

I run mySQL

With similar, I mean like to find their similarity percentage are more of a specified value. Like if the first contains this is a string and second i wear a string there is a percentage of similarity. If this % is more than 70 then they are similar.

Answer 1

there are many ways, here is one that will give you all the products that match your criteria (first = second)

SELECT
  t1.name AS first, t2.name AS second 
FROM
  products t1, products t2
WHERE
  t1.name = t2.name

or, if you need all the values

Select
  t1.name as first t2.name as second, (if t1.name = t2.name THEN 1 ELSE 0) as match
From 
  products t1, products t2