How could i search between two string type date Consider these two tables. I use persian dates, so I have to declare startdate and enddate as a string(nvarchar(10)).

crt table:

id title startdate enddate
--------------------------
1  xyz   1395/01/01  1395/12/29
2  xyy   1394/12/01  1395/05/05
3  cvb   1392/02/03  1394/02/03


season table:

id title startdate enddate
--------------------------
1  spring95 1395/01/01  1395/03/31


I want to write a query that gives me crt records that are valid in a season. IE crt.startdate&lt;=season.startdate and crt.enddate&gt;=season.enddate.

How do I do that?
If you encounter performance problems you could store the dates as integers instead of varchar. 1397-12-09 becomes 13971209, all the numbers remain in sequence so you can still carry out BETWEEN queries. Then convert your results to date format at the final point of presentation.