SQLiteSUM语句

SELECT SUM(aggregate_expression)
FROM tables
[WHERE conditions]; 

SELECT expression1, expression2, ... expression_n
SUM(aggregate_expression)
FROM tables
[WHERE conditions]
GROUP BY expression1, expression2, ... expression_n;

SELECT SUM(FEES) AS "Total Fees"
FROM STUDENT
WHERE ID <= 5; 

SELECT SUM(FEES/12) AS "Total Monthly Fees"
FROM STUDENT;

SELECT ADDRESS, SUM(FEES) AS "Total Salary"
FROM STUDENT
WHERE ID <= 5
GROUP BY ADDRESS;