Applies to: ✅ Data 360 SQL ✅ Tableau Hyper API
Counts the number of input rows or non-null values.
Syntax
count(*)
count(<expression>)
count(DISTINCT <expression>)
Arguments
Required
*: Counts all rows, including rows with NULL values.<expression>: Counts rows where the expression is not NULL.
Optional
DISTINCT: Counts only distinct non-null values.
Returns
Returns a bigint representing the count.
Considerations
- Unlike other aggregates,
countreturns 0 (not NULL) for empty sets.
Examples
Count All Rows
Count the total number of rows.
SELECT count(*) AS total_orders
FROM orders;
Count Non-NULL Values
Count the rows with non-null values.
SELECT count(email) AS customers_with_email
FROM customers;
Count Distinct Values
Count the unique values.
SELECT count(DISTINCT category) AS category_count
FROM products;
Count by Group
Count the rows per group.
SELECT department, count(*) AS employee_count
FROM employees
GROUP BY department;