form子句語法錯誤

HAVING gives the DBA or SQL-using programmer a way to filter the data aggregated by the GROUP BY clause so that the user gets a limited set of records to view.

HAVING為DBA或使用SQL的程序員提供了一種過濾由GROUP BY子句聚合的數據的方法，以便用戶可以查看一組有限的記錄。

使用例 (Example of use)

The HAVING clause is like the WHERE clause, except it acts on the grouped data. In this case, the user will only see the largest amounts.

HAVING子句與WHERE子句類似，不同之處在于它對分組的數據起作用。 在這種情況下，用戶只會看到最大的金額。

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 contributions in 2016 BUT only those that had more than 8$20 Million USD?”

該SQL語句回答了以下問題：“哪些候選人在2016年BUT中獲得的捐款最多，只有那些收入超過8千萬美元的候選人？”

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/the-sql-having-clause-explained-with-example-syntax/

form子句語法錯誤