group_concat and how to use row number in sqlite

问题

i have a data in a table, column id and column date

id  || datetime
1   || 2013-05-24 19:23:16
2   || 2013-05-28 19:24:20
3   || 2013-05-28 19:25:05  
4   || 2013-05-30 19:25:39  
5   || 2013-05-30 19:26:05

how query to show only one day with count?or one row with count. so the result is.

    || datetime            || count
1   || 2013-05-24 19:23:16 ||  1
2   || 2013-05-28 19:24:20 ||  2
3   || 2013-05-30 19:25:39 ||  2

i try in mysql and it works , there is my query.

SELECT id, GROUP_CONCAT( datetime ) AS date, COUNT( id ) AS count
FROM dataPetak
GROUP BY DATE( datetime )

but when i use sqlite the result is gives me all in one string

5 || 2013-05-24 19:23:16,2013-05-28 19:24:20,2013-05-28 19:25:05,2013-05-30 19:25:39,2013-05-30 19:26:05 || 5

how to fix that?

help me

EDIT

when i use query

SELECT [datetime], [count] FROM (SELECT MAX([datetime]) 'datetime', COUN
T(*) 'count' FROM dataPetak GROUP BY CAST ([datetime] AS DATE)) t;

the result is

       2013-05-24 19:23:16 ||  1
       2013-05-28 19:24:20 ||  2
       2013-05-30 19:25:39 ||  2

how to use row number in sqlite?

so the result is

1   || 2013-05-24 19:23:16 ||  1
2   || 2013-05-28 19:24:20 ||  2
3   || 2013-05-30 19:25:39 ||  2

when i try this query ,

SELECT ROW_NUMBER () OVER (ORDER BY [datetime]) No, [datetime], [count] FROM (SELECT MAX([datetime]) 'datetime', COUN
T(*) 'count' FROM dataPetak GROUP BY CAST ([datetime] AS DATE)) t;

show the error

Error: near "(": syntax error

how to fix that?

回答1:

There is no need for GROUP_CONCAT() functionality in your case. Your last query in the question is for SQL Server. Sqlite doesn't have implementation for ROW_NUMBER().

This being said, try

SELECT 
 (
   SELECT COUNT(*) 
     FROM 
   ( SELECT 1
       FROM dataPetak
      WHERE id <= t.id
      GROUP BY DATE(datetime)
   ) q
 ) No, datetime, count
  FROM 
 (
   SELECT id, MIN(datetime) datetime, COUNT(*) count
     FROM dataPetak
    GROUP BY DATE(datetime)   
 ) t

Output:

| No |            datetime | count |
------------------------------------
|  1 | 2013-05-24 19:23:16 |     1 |
|  2 | 2013-05-28 19:24:20 |     2 |
|  3 | 2013-05-30 19:25:39 |     2 |

Here is SQLFiddle demo

回答2:

Try this query

select date(datetime) as date,  count(*) as count from tbl 

group by date(datetime)

FIDDLE

|       date | count |
----------------------
| 2013-05-24 |     1 |
| 2013-05-28 |     2 |
| 2013-05-30 |     2 |

来源：https://stackoverflow.com/questions/16837958/group-concat-and-how-to-use-row-number-in-sqlite

标签

sql

sqlite

android-sqlite

group-concat