how to select unique in sql code example

Example 1: MySQL DISTINCT

When querying data from a table, you may get duplicate rows. In order to remove these duplicate rows, you use the DISTINCT clause in the SELECT statement.

Here is the syntax of the DISTINCT clause:

SELECT DISTINCT
    select_list
FROM
    table_name;

Example 2: query DISTINCT

SELECT DISTINCT Column_name FROM table_name;

Example 3: unique element in sql

DISTINCT
- select distinct * from employees; ==> retrieves any row if it has at
least a single unique column.
- select distinct first_name from employees; ==> retrieves unique names
from table. (removes duplicates)
- select distinct count(*) from employees; retrieve number of unique rows
if any row has at least a single unique data.