Revising Aggregations - The Count Function-MySQL HackerRank Solution

Query a count of the number of cities in CITY having a Population larger than 100,000.

Input Format

The CITY table is described as follows:

Solution

 

 
  SELECT COUNT(NAME)

  FROM CITY 

  WHERE POPULATION>100000

 

SELECT is the SQL keyword that lets the database know that you want to retrieve data.

COUNT() function is used to returns the count of an expression. It allows us to count all rows or only some rows of the table that matches a specified condition. It is a type of aggregate function whose return type is BIGINT. This function returns 0 if it does not find any matching rows.