How to select records without duplicate on just one field in SQL?

Try this:

SELECT MIN(id) AS id, titleFROM tbl_countriesGROUP BY title

DISTINCT is the keyword
For me your query is correct

Just try to do this first

SELECT DISTINCT title,id FROM tbl_countries

Later on you can try with order by.

For using DISTINCT keyword, you can use it like this:

SELECT DISTINCT     (SELECT min(ti.Country_id)      FROM tbl_countries ti      WHERE t.country_title = ti.country_title) As Country_id    , country_titleFROM     tbl_countries t

For using ROW_NUMBER(), you can use it like this:

SELECT     Country_id, country_title FROM (    SELECT *, ROW_NUMBER() OVER (PARTITION BY country_title ORDER BY Country_id) As rn    FROM tbl_countries) tWHERE rn = 1

Also with using LEFT JOIN, you can use this:

SELECT t1.Country_id, t1.country_titleFROM tbl_countries t1    LEFT OUTER JOIN    tbl_countries t2 ON t1.country_title = t2.country_title AND t1.Country_id > t2.Country_idWHERE    t2.country_title IS NULL

And with using of EXISTS, you can try:

SELECT t1.Country_id, t1.country_titleFROM tbl_countries t1   WHERE    NOT EXISTS (SELECT 1                 FROM tbl_countries t2                 WHERE t1.country_title = t2.country_title AND t1.Country_id > t2.Country_id)