Question

I have an iOS app that takes use of SQLite. I use FireFox and the plugin SQLite Manager for managing the database.

Now I have a table like this:

CREATE TABLE "someTable" ("id" INTEGER NOT NULL , "timeOfEvent" DATETIME NOT NULL)

I am however able to input practically any value I want into the DateTime column like so:

INSERT INTO sometable (id, timeOfEvent) VALUES (1,'2012-99-99')
INSERT INTO sometable (id, timeOfEvent) VALUES (2,'yyyy-mm-dd')
...etc

Why is this possible?

Answer 1

As per the documentation: SQLite- Data Types

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
• 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.

Thus SQLite relies on methods to convert the values. It doesn’t have it’s own data type to restrict date/time type.