SQL(ANSI) - takt@Wiki

• EXTRACT

日付・時間の抽出

select EXTRACT( {YEAR | MONTH | DAY} FROM sysdate) from dual;
select EXTRACT( {HOUR | MINUTE| SECOND} FROM systimestamp) from dual;

• COALESCE

最初のNULL値でない値を返す

select COALESCE(null, val1, val2, val3) from dual;