如何在SQLite3中将日期时间字符串转换为UNIX时间戳？

Question

The documentation for SQLite3 datatypes says

the built-in Date And Time Functions of SQLite are capable of storing dates and times as TEXT, REAL, or INTEGER values

I want to use those functions to store INTEGER values. How do I do so? The documentation for SQLite3 datetime functions describes the types of the arguments to those functions, but says nothing of the return type. It seems that the return type is text :

sqlite> select typeOf(datetime('2014-12-12 12:12:12.000'));
text

This is not what I want -- I want an integer value representing that time as a UNIX timestamp. Even when I create a column of type integer and attempt to store a datetime(...) value in it, SQLite stores it as a text value in that integer column.

How do I force the datetime function and friends to return a UNIX timestamp, instead of a text value?

Answer 1

All the built-in date/time functions return strings.

To convert a string into a number, use CAST :

SELECT CAST(strftime('%s', 'now') AS INT);