sql sum语句
SQL中的Sum语句是什么? (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.
这是合计函数之一(如计数,平均值,最大值,最小值等)。 它们在GROUP BY子句中使用,因为它聚集了语句的SELECT FROM WHERE部分提供的数据。
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语句中的“ sum(Total_ $)”汇总在GROUP BY子句中。 “ Count(*)”提供了捐款数量。
This data is from the campaign contributions data we’ve been using in some of these guides.
此数据来自我们在其中一些指南中一直使用的广告系列贡献数据。
This SQL statement is answering the question: “which candidates received the largest total contribution dollars in 2016 BUT only those that had more than $20 Million USD for all contributions combined?”
该SQL语句回答了以下问题:“哪些候选人在2016年BUT中获得的捐款总额最多,而所有捐款加起来超过2000万美元的候选人呢?”
Ordering this data set in a descending (DESC) order places the candidates with the largest total contributions at the top of the list.
按降序(DESC)排序此数据集,将总贡献最大的候选者放在列表的顶部。
SELECT Candidate, Election_year, sum(Total_$), 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.
与所有这些SQL事物一样,它们比本入门指南中的内容要多得多。
I hope this at least gives you enough to get started.
我希望这至少能给您足够的入门。
Please see the manual for your database manager and have fun trying different options yourself.
请参阅数据库管理员的手册,并尝试自己尝试其他选项,这很有趣。
翻译自: https://www.freecodecamp/news/sql-sum-statements-explained-with-examples/
sql sum语句
更多推荐
sql sum语句_SQL Sum语句示例说明
发布评论