sql sum語句

SQL中的Sum語句是什么？ (What is the Sum statement in SQL?)

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.

這是合計函數之一(如計數，平均值，最大值，最小值等)。 它們在GROUP BY子句中使用，因為它聚集了語句的SELECT FROM WHERE部分提供的數據。

使用例 (Example of use)

“sum(Total_$)” in the SELECT statement is aggregated in the GROUP BY clause. “Count(*)” provides the number of contributions.

SELECT語句中的“ sum(Total_ $)”匯總在GROUP BY子句中。 “ Count(*)”提供了捐款數量。

This data is from the campaign contributions data we’ve been using in some of these guides.

此數據來自我們在其中一些指南中一直使用的廣告系列貢獻數據。

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?”

該SQL語句回答了以下問題：“哪些候選人在2016年BUT中獲得的捐款總額最多，而所有捐款加起來超過2000萬美元的候選人呢？”

Ordering this data set in a descending (DESC) order places the candidates with the largest total contributions at the top of the list.

按降序(DESC)排序此數據集，將總貢獻最大的候選者放在列表的頂部。

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.

+--------------------------------------------------+---------------+-------------------+----------+
| 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.

與所有這些SQL事物一樣，它們比本入門指南中的內容要多得多。

I hope this at least gives you enough to get started.

我希望這至少能給您足夠的入門。

Please see the manual for your database manager and have fun trying different options yourself.

請參閱數據庫管理員的手冊，并嘗試自己嘗試其他選項，這很有趣。

翻譯自: https://www.freecodecamp.org/news/sql-sum-statements-explained-with-examples/

sql sum語句