sql sum code example

Example 1: sql count

/*COUNT(column_name) will return the number of rows from the column 
that are not NULL*/
SELECT COUNT(column_name)
FROM table_name;

/*COUNT(*) will return the number of rows from the table*/
SELECT COUNT(*)
FROM table_name;

Example 2: sql sum and other fields

SELECT sum(a) as car,b,c FROM toys 
GROUP BY b, c