SQL: Statement Fundamentals - COUNT

---

SQL: Statement Fundamentals

COUNT

The COUNT function returns the number of input rows that match a specific condition of a query.

Syntax:

-- COUNT
SELECT COUNT(*)/ COUNT(column)/ COUNT(DISTINCT column)
FROM table;

Example: Number of transactions in the payment table

-- Count the number of transactions in the payment table
SELECT COUNT(*)
FROM payment;

##   count
## 1 14596

Example: Number of distinct transactions in the payment table

-- Count the number of transactions in the payment table
SELECT COUNT(DISTINCT(amount))
FROM payment;

##   count
## 1    19