COUNT with condition and group : Count « Select Clause « SQL / MySQL






  1. SQL / MySQL
  2. Select Clause
  3. Count

COUNT with condition and group

/*
mysql> SELECT species, sex, COUNT(*) FROM Bird
    ->     WHERE sex IS NOT NULL
    ->     GROUP BY species, sex;
+---------+------+----------+
| species | sex  | COUNT(*) |
+---------+------+----------+
| Bus     | m    |        2 |
| Car     | f    |        1 |
+---------+------+----------+
2 rows in set (0.00 sec)


*/  
Drop table Bird;

CREATE TABLE Bird (
    name VARCHAR(20), 
    owner VARCHAR(20),
    species VARCHAR(20), 
    sex CHAR(1), 
    birth DATE, 
    death DATE
);
  
INSERT INTO  Bird VALUES ('BlueBird','Joe','Car','f','1999-03-30',NULL);
INSERT INTO  Bird VALUES ('RedBird','Yin','Bus','m','1979-04-30',1998-01-30);
INSERT INTO  Bird VALUES ('RedBird','Yin','Bus','m','1998-01-30',NULL);

/* Or, if you wanted the number of animals per sex only for animals whose 

sex is known:
*/

SELECT species, sex, COUNT(*) FROM Bird
    WHERE sex IS NOT NULL
    GROUP BY species, sex;








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7.COUNT command with condition
8.Get GROUP BY for COUNT
9.Use COUNT with condition
10.Simple COUNT
11.Performing Row and Column Counting
12.Use COUNT and GROUP
13.Use COUNT, GROUP and HAVING