SQLite compare dates - sql

Question

I have this SQL-Statement:
SELECT Geburtsdatum FROM Kunde
WHERE Geburtsdatum BETWEEN '1993-01-01' AND '2000-01-01'
but I get some weird results, like: 2.02.1990
'Geburtsdatum' is a DATE
Any suggestions or solutions?
my table-structure:
CREATE TABLE Kunde (
Kunde_ID INTEGER NOT NULL ,
Card INTEGER ,
Vorname VARCHAR(255) NOT NULL ,
Nachname VARCHAR(255) NOT NULL ,
Ort VARCHAR(255) NOT NULL ,
Strasse VARCHAR(255) NOT NULL ,
Postleitzahl VARCHAR(10) NOT NULL ,
Mail VARCHAR(255) ,
Telefonnummer VARCHAR(255) ,
Geburtsdatum DATE NOT NULL ,
Beitrittsdatum DATE NOT NULL ,
Geschlecht INTEGER NOT NULL ,
Land VARCHAR(255) NOT NULL DEFAULT 'Österreich' ,
Bankname VARCHAR(255) ,
Bankleitzahl VARCHAR(255) ,
Kontonummer VARCHAR(255) ,
GroupID INTEGER NOT NULL ,
Besucher INTEGER ,
Access BOOLEAN ,
image BLOB NULL ,
writeDate DATE ,
drinkAbo BOOLEAN ,
PRIMARY KEY (Kunde_ID) )

Answer 1

From the documentation:
SQLite does not have a storage class set aside for storing dates and/or times.
So your column isn't exactly stored as a date. Reading further, we learn that columns specifed as DATE are actually stored as NUMERIC using affinity rule 5.
Going back up to section 1.2:
REAL as Julian day numbers, the number of days since noon in Greenwich on November 24, 4714 B.C. according to the proleptic Gregorian calendar.
Good. So let's try:
SELECT Geburtsdatum FROM Kunde
WHERE Geburtsdatum
BETWEEN julianday('1993-01-01') AND julianday('2000-01-01');
Oddly enough, SQL Fiddle seems to store DATEs as strings and the above doesn't work. In this case, the following should:
SELECT Geburtsdatum FROM Kunde
WHERE date(Geburtsdatum)
BETWEEN date('1993-01-01') AND date('2000-01-01');
Additionally, in your case you seem to be getting some strange (read: localized) format returned. I wonder if it really is a string in your case too, just with a different format. You could try:
SELECT Geburtsdatum FROM Kunde
WHERE strftime('%d.%m.%Y', Geburtsdatum)
BETWEEN date('1993-01-01') AND date('2000-01-01');

Answer 2

Someone had the same problem and got it resolved. (use datetime function before comparison)
See SQLite DateTime comparison
Excerpt:
Following the datetime function and having a string format as YYYY-MM-DD HH:mm:ss i achieved good results as follows
select *
from table_1
where mydate >= Datetime('2009-11-13 00:00:00')
and mydate <= Datetime('2009-11-15 00:00:00')
--EDIT--
You are basically comparing strings. Which is why the unexpected behavior. Convert to datetime using the function right before comparison and it should work.

Answer 3

To be able to compare dates, you must store them in one of SQLite's supported date formats, such as a JJJJ-MM-TT string. Your dates are stored as strings in a localized date format which is not recognized by SQLite.
If the most significant field is not at the start of the string, string comparisons will not work for dates.
With the values currently in your table, you will not be able to do any comparisons.