sql query group by day of month

Question

I have a record table that icludes dates of rows created. (oracle db)

ID    City       CreateDate
1     city-1     12.12.2017
1     city-2     13.12.2017
1     city-1     13.12.2017
1     city-3     12.12.2017
....
....

I want to create a daiy report in a month. For example City-1 report by days in December

Day    Count
1      10
2      80
3      60
4      10
...
30     11

Answer 1

I think you can use extract with count functions:

SELECT EXTRACT(day FROM CreateDate) "Day",
      COUNT(CreateDate) "Number of Reports"
      FROM yourTableName
      GROUP BY EXTRACT(day FROM CreateDate)
      ORDER BY "Number of Reports" ASC;

Answer 2

如果我正确理解，以下查询将生成您想要的12月份的报告。

SELECT EXTRACT(day FROM CreateDate) "Day", COUNT(*) "Count" FROM your_record_table WHERE EXTRACT(month FROM CreateDate) = 12 GROUP BY EXTRACT(day FROM CreateDate) ORDER BY EXTRACT(day FROM CreateDate);