SQL DISTINCT Command

SELECT DISTINCT class FROM student

SELECT DISTINCT class FROM student 

Counting number of distinct records

SELECT COUNT( DISTINCT class ) FROM student

MySQL Count Query

Null value with DISTINCT

DISTINCT query using more than one column of a table

SELECT distinct class, gender FROM `student`

SELECT distinct class, gender FROM `student` order by class

Distinct records linking two tables.

SELECT DISTINCT sale.c_id, name FROM  `sale` , customer WHERE sale.c_id = customer.c_id 

Unique data from two columns

SELECT Team_1 FROM icc_world_cup
UNION
SELECT Team_2 FROM icc_world_cup

Team_1	
India
SL
SA
Eng
Aus
NZ

CREATE TABLE `icc_world_cup` (
  `Team_1` varchar(20) DEFAULT NULL,
  `Team_2` varchar(20) DEFAULT NULL,
  `Winner` varchar(20) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

--
-- Dumping data for table `icc_world_cup`
--

INSERT INTO `icc_world_cup` (`Team_1`, `Team_2`, `Winner`) VALUES
('India', 'SL', 'India'),
('SL', 'Aus', 'Aus'),
('SA', 'Eng', 'Eng'),
('Eng', 'NZ', 'NZ'),
('Aus', 'India', 'India');

Present in one and not present in other table.

PHP Script to use Distinct SQL

<?Php
require "config.php";// Database connection

$count="SELECT DISTINCT class, gender FROM student ORDER BY class";

echo "<table>";
echo "<tr><th>class</th><th>gender</th></tr>";
foreach ($dbo->query($count) as $row) {
echo "<tr ><td>$row[class]</td><td>$row[gender]</td></tr>";
}
echo "</table>";
?>

Python script

from sqlalchemy import create_engine
from sqlalchemy.exc import SQLAlchemyError
my_conn = create_engine("mysql+mysqldb://root:pw@localhost/db")
try:
    r_set=my_conn.execute('SELECT DISTINCT class FROM student') 
    for row in r_set:
        print(row[0])
except OSError as e:
    print(e) # Specific error message 
    print ("Failed to delete %s " % path)
else:
    print ("Successfully Executed ")