if you are storing dates as strings in the format
YYYY-MM-DD HH:mm:ss
====> then your date field is a DateTime datatype
Thus you have to use such query
select *
from MyTable
where mydate >= Datetime('2000-01-01 00:00:00')
and mydate <= Datetime('2050-01-01 23:00:59')
you can also use the snippet given by @Joop Eggen with th between operator it’s th same approche.
The BETWEEN operator is logically equivalent to a pair of comparisons. “x BETWEEN y AND z” is equivalent to “x>=y AND x<=z” except that with BETWEEN, the x expression is only evaluated once. see sqlite3 docs