MySQL count function
MySQL count function
The COUNT() function returns the number of rows that matches a specified criteria.
COUNT function to count the number rows in a table.
The return type of the COUNT function is BIGINT. The COUNT function will return zero if there was no matching row found.
The COUNT(*) function returns the number of rows in a result set returned by a SELECT statement. The COUNT(*) function counts rows that contain non-NULL and NULL values.
If you use the COUNT(*) function to count the rows in a table without using a WHERE clause and selecting other columns, it will perform very fast.
COUNT() Syntax
SELECT COUNT(column_name)
FROM table_name
WHERE condition;Query example:
SELECT COUNT(IF(status=‘Cancelled’,1, NULL)) ‘Cancelled’, COUNT(IF(status=‘On Hold’,1, NULL)) ‘On Hold’, COUNT(IF(status=‘Disputed’,1, NULL)) ‘Disputed’FROM orders;SELECT productvendor, count(*)
FROM products
GROUP BY productvendor
HAVING count(*) >= 9;
SELECT productvendor, count(*)
FROM products
GROUP BY productvendor;
SELECT COUNT(ProductID)
FROM Products;
FROM Products;
