--- title: SQL Sum Function --- ## SQL Sum Function This is one of the aggregate functions (as is count, average, max, min, etc.). They are used in a GROUP BY clause as it aggregates data presented by the SELECT FROM WHERE portion of the statement. ### Example of use "sum(Total_$)" in the SELECT statement is aggregated in the GROUP BY clause. "Count(\*)" provides the number of contributions. This data is from the campaign contributions data we've been using in some of these guides. This SQL statement is answering the question: "which candidates received the largest total contribution dollars in 2016 BUT only those that had more than $20 Million USD for all contributions combined?" Ordering this data set in a descending (DESC) order places the candidates with the largest total contributions at the top of the list. ```sql SELECT Candidate, Election_year, sum(Total_$), count(*) FROM combined_party_data WHERE Election_year = 2016 GROUP BY Candidate, Election_year -- this tells the DBMS to summarize by these two columns HAVING sum(Total_$) > 20000000 -- limits the rows presented from the summary of money ($20 Million USD) ORDER BY sum(Total_$) DESC; -- orders the presented rows with the largest ones first. ``` ```text +--------------------------------------------------+---------------+-------------------+----------+ | Candidate | Election_year | sum(Total_$) | count(*) | +--------------------------------------------------+---------------+-------------------+----------+ | CLINTON, HILLARY RODHAM & KAINE, TIMOTHY M (TIM) | 2016 | 568135094.4400003 | 126 | | TRUMP, DONALD J & PENCE, MICHAEL R (MIKE) | 2016 | 366853142.7899999 | 114 | | SANDERS, BERNARD (BERNIE) | 2016 | 258562022.17 | 122 | | CRUZ, RAFAEL EDWARD (TED) | 2016 | 93430700.29000005 | 104 | | CARSON, BENJAMIN S (BEN) | 2016 | 62202411.12999996 | 93 | | RUBIO, MARCO ANTONIO | 2016 | 44384313.9 | 106 | | BUSH, JOHN ELLIS (JEB) | 2016 | 34606731.78 | 97 | +--------------------------------------------------+---------------+-------------------+----------+ 7 rows in set (0.01 sec) ``` As with all of these SQL things there is MUCH MORE to them than what's in this introductory guide. I hope this at least gives you enough to get started. Please see the manual for your database manager and have fun trying different options yourself.