Verify the date exits between dates and pick the specific row based on type

Question

TableA

id        dtchk
1001    3/31/2018
1002    9/30/2018
1004    3/31/2019
1003    5/25/2018
1005    9/30/2019
1006    3/31/2020

TableB

id     type  startdate  endate      name
1001    1    4/5/2018   12/31/2025  akshi
1002    100  4/27/2015  12/31/2023  polard
1004    100  4/1/2017   12/31/2019  kathi
1003    1    1/25/2018  5/25/2019   smoth
1005    1    3/21/2017  12/31/2020  sumi
1005    100  3/26/2019  12/31/2021  chechi
1006    1    2/28/2019  3/31/2021   paul
1006    100  2/28/2017  3/31/2019   rand

First we need to verify dtchk is between startdate and endate based on id if date eists between those dates then we need check the types if types 1 & 100 both fits then pick row with type 100 else pick as is if the date fits in those dates

output

id      name
1002    polard
1004    kathi
1003    smoth
1005    chechi
1006    paul

Answer 1

I think you want apply :

select a.*, b.*
from a cross apply
     (select top (1) with ties b.*
      from b
      where b.id = a.id and
            a.dtchk between b.startdate and b.endate and
            b.type in (1, 100)
      order by b.type desc
     ) b;