Oracle SQL | Group by Date

Das folgende Oracle-SQL gruppiert die fehlgeschlagenen Datensätze aus der Tabelle 'tabelle_mit_datum' nach Jahr, Monat und Tag:

SELECT
    COUNT(*) AnzahlFehler,
    TO_CHAR(cs.datum, 'YYYY') Jahr,
    TO_CHAR(cs.datum, 'MM') Monat,
    TO_CHAR(cs.datum, 'DD') Tag,
FROM
    tabelle_mit_datum tmd
WHERE
    tmd.status = 'Fehler'
    AND tmd.datum BETWEEN
        TO_DATE('01.01.2017', 'DD.MM.YYYY')
        AND TO_DATE('30.04.2017', 'DD.MM.YYYY')
GROUP BY
    TO_CHAR(cs.datum, 'YYYY') Jahr,
    TO_CHAR(cs.datum, 'MM') Monat,
    TO_CHAR(cs.datum, 'DD') Tag,
ORDER BY
    TO_CHAR(cs.datum, 'YYYY') Jahr DESC,
    TO_CHAR(cs.datum, 'MM') Monat DESC,
    TO_CHAR(cs.datum, 'DD') Tag DESC
;

Oracles TO_CHAR(date, dateformat) Funktion kann einige tolle Sachen. Der folgende Ausdruck liefert die Woche des Jahres zurück:

SELECT TO_CHAR(sysdate, 'IW') FROM dual;

Folgende Formate stehen als Parameter zur Verfügung:

YEAR	Year, spelled out
YYYY	4-digit year
YYY	Last 3 digits of year.
YY	Last 2 digits of year.
Y	Last digit of year.
IYY	Last 3 digits of ISO year.
IY	Last 2 digits of ISO year.
I	Last 1 digit of ISO year.
IYYY	4-digit year based on the ISO standard
Q	Quarter of year (1, 2, 3, 4; JAN-MAR = 1).
MM	Month (01-12; JAN = 01).
MON	Abbreviated name of month.
MONTH	Name of month, padded with blanks to length of 9 characters.
RM	Roman numeral month (I-XII; JAN = I).
WW	Week of year (1-53) where week 1 starts on the first day of the year and continues to the seventh day of the year.
W	Week of month (1-5) where week 1 starts on the first day of the month and ends on the seventh.
IW	Week of year (1-52 or 1-53) based on the ISO standard.
D	Day of week (1-7).
DAY	Name of day.
DD	Day of month (1-31).
DDD	Day of year (1-366).
DY	Abbreviated name of day.
J	Julian day; the number of days since January 1, 4712 BC.
HH	Hour of day (1-12).
HH12	Hour of day (1-12).
HH24	Hour of day (0-23).
MI	Minute (0-59).
SS	Second (0-59).
SSSSS	Seconds past midnight (0-86399).
FF	Fractional seconds.