mysql comparision

can you elaborate on your comparison criteria?

Text string

Word1 word2 word3
Word2 word2 word2

What is numerical similarly percentage.
Or what are possible mysql functions

Okay the only thing built-in to MySQL that you can use is the full-text functions.  Not sure if that will satisfy your requirement but see http://dev.mysql.com/doc/refman/5.1/en/fulltext-natural-language.html.  Basically, assuming column1 is the one with the full-text index, you should be able to do something like:

SELECT  column1, column2, MATCH (column1)
AGAINST (column2 IN NATURAL LANGUAGE MODE) AS score
FROM tablename;

Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'NATURAL LANGUAGE MODE) AS score
FROM table' at line 2

Please post complete information so that we can help you better.  In this case - can you post your complete SQL?

comparing fields from the same column

field1='hello, how are you'
field2='very different'
field3='hi, how are you'
field4='another string

You gave me an error message you encountered when you ran a query - I asked for that complete query, not the data you are running it on.

I ran this query and substituted my table and column name

query:

SELECT  column1, column2, MATCH (column1)
AGAINST (column2 IN NATURAL LANGUAGE MODE) AS score
FROM tablename;

ok sorry but it looks like MySQL won't accept a column name as a parameter in AGAINST().  You will have to make a script that reads each row and runs that full-text function for each.  Based on your previous questions I participated in you are on Windows, and I unfortunately cannot help you make a script on that platform.

I am using linux for this

Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'NATURAL LANGUAGE MODE) AS score


what do I put for 'very different'

thanks

I will look into comparison further