Sqlite date between - sqlite

Question

can you please help me why this code does not work?
I dont understand why the result include "2017".
SQLLITE
QUERY
SELECT issue_date as count FROM tablename where issue_date >= "08/08/2016" and issue_date < "09/01/2016"
Result
"08/08/2017"
"08/11/2017"
"08/18/2017"
"08/18/2017"
"08/22/2017"
"08/22/2017"
"08/28/2017"
"08/31/2017"
Create query
CREATE TABLE tablename (
issue_date datetime text not null
}
Insert query
INSERT INTO tablename (issue_date) values ("08/31/2017");

Answer 1

You are storing your dates in a non ANSI compliant format. As there is no formal date type in SQLite, and all dates are essentially stored as strings, your current date comparison will behave and sort as if you are comparing to text. It won't work, because you have the month first, followed by the day, followed by the year. To get text comparisons of dates to work correctly, use a format something like this:
yyyy-mm-dd
You should change the format you use to store dates, but one workaround would be to build the issue date in the correct format and then do the comparison, also against a date string in the same correct format:
SELECT
issue_date AS count
FROM tablename
WHERE
SUBSTR(issue_date, 7, 4) || '-' ||
SUBSTR(issue_date, 1, 2) || '-' ||
SUBSTR(issue_date, 4, 2) BETWEEN '2016-08-08' AND '2016-09-01'

Answer 2

SQLite's data types does not have a real DATETIME type. It only has NULL, INTEGER, REAL, TEXT and BLOB. Any other type is converted to these, so what it is doing in your case is storing those values as strings, and this comparing as strings.
I personally prefer to store the dates as UNIX timestamps (hence integers) to avoid complicating the SQL queries and simplify the whole thing (although the values in database will become less human-readable).

Answer 3

Because you specified the query with AND. So it matches your query. Use BETWEEN expression.
expression BETWEEN value1 AND value2;