When fetching data from a database table, the result set may contain duplicate rows or values. If you want to remove these duplicate values you can specify the keyword DISTINCT directly after the SELECT keyword, as demonstrated below:
DISTINCT clause is used to remove duplicate rows from the result set:
Here, column_list is a comma separated list of column or field names of a database table (e.g. name, age, country, etc.) whose values you want to fetch.
SELECT city FROM customers;
If you see the output carefully, you'll find the city "Madrid" appears two times in our result set, which is not good. Well, let's fix this problem.
The following statement uses
DISTINCT to generate a list of all city in the customers table.
SELECT DISTINCT city FROM customers;