MariaDB COUNT
To get the count of an expression, the MariaDB COUNT function is used.
Syntax:
SELECT expressions, COUNT (aggregate_expression) FROM table_name WHERE conditions;
Parameters:
Aggregate_expression: It is used to specify the column or expression to be utilised by the aggregate function.
Example 1: Using Group By Clause.
Players Table:
ID NAME SPORTS 1 Sachin Cricket 2 Dhoni Cricket 3 Sunil Football 4 Srikanth Badminton 5 Mary Boxing
Query:
SELECT sports, COUNT(*) AS “Number of Players” FROM Players GROUP BY sports; |
Output:
SPORTS Number of Players Cricket 2 Football 1 Badminton 1 Boxing 1
Explanation:
The ‘Players’ is an already existing table. Here we are counting the number of players in the same SPORTS group, using the Group By clause with an aggregate function COUNT.
Example 2: Using Distinct Clause.
Players Table:
ID NAME SPORTS 1 Sachin Cricket 2 Dhoni Cricket 3 Sunil Football 4 Srikanth Badminton 5 Mary Boxing
Query:
SELECT COUNT(DISTINCT sports) FROM Players; |
Output:
4 |
Explanation:
The ‘Players’ is an already existing table. Here we are counting the number of unique values in the SPORTS column, using the Distinct clause with an aggregate function COUNT.
Example 3:
Players Table:
ID NAME SPORTS 1 Sachin Cricket 2 Dhoni Cricket 3 Sunil Football 4 Srikanth 5 Mary Boxing
Query:
SELECT COUNT(sports) FROM Players; |
Output:
4 |
Explanation:
The count of the total number of NOT NULL values in the SPORTS column is 4 and so is the result.