SQLite allows insert of string data into datetime column - sql

Question

Table:
CREATE TABLE logaction
(
actype varchar(8) not null,
actime DATETIME not null,
devid int not null
);
SQL:
insert into logaction values ('TEST', '2013-08-22', 1);
insert into logaction values ('TEST', '2013-08-22 09:45:30', 1);
insert into logaction values ('TEST', 'xyz', 2); // shouldn't this fail?
The last record does make it into the table regardless of the non-datetime value for the actime column. Why and how can I enforce that only good data go in?
Here is a SQL Fiddle.

Answer 1

Well, there's just no DATETIME type in Sqlite...
SQLite does not have a storage class set aside for storing dates
and/or times. Instead, the built-in Date And Time Functions of SQLite
are capable of storing dates and times as TEXT, REAL, or INTEGER
values:
TEXT as ISO8601 strings ("YYYY-MM-DD HH:MM:SS.SSS").
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.
INTEGER as Unix Time, the number of seconds since 1970-01-01 00:00:00 UTC.
Applications can chose to store dates and times in any of these
formats and freely convert between formats using the built-in date and
time functions.
see doc
You could have created your table like that, it wouldn't have changed anything.
CREATE TABLE logaction
(
actype varchar(8) not null,
actime NonexistingType not null,
devid int not null
);

Answer 2

Unfortunately, not really in sqlite - it doesn't have a datetime type - see section 1.2 in here

Answer 3

Here's a simple work around:
CREATE TABLE logaction
(
actype varchar(8) not null,
actime DATETIME not null check( DATETIME(actime) is not null ),
devid int not null
);
sqlite> insert into logaction values ('TEST', '2013-08-22', 1);
sqlite> insert into logaction values ('TEST', '2013-08-22 09:45:30', 1);
sqlite> insert into logaction values ('TEST', 'xyz', 2);
Error: constraint failed
sqlite>