SQL
SELECT TO_CHAR( entry_date, 'YYYYMMDD' ) as DAY, COUNT( TO_CHAR(entry_date, 'YYYYMMDD') ) as COUNT FROM test_table GROUP BY DAY ORDER BY DAY;
select name,email,( case EXTRACT(DOW FROM date) when 0 then '日' when 1 then '月' when 2 then '火' when 3 then '水' when 4 then '木' when 5 then '金' when 6 then '土' end ) as day FROM test_table ;http://www.sraoss.co.jp/PostgreSQL/Manual/…