MSSQL，如何将记录与 dataframe 表进行比较？

Question

let's say we have a table with invoices and employees ID

and another table for vacation which also contains an employee ID. In this case only emplyee1 had vacation a these date frames.

Now we have to compare if the invoice date is between or exactly at the date frames of vacation table.

The aim is: The invoice date has to be compared, if an employee is on vacation the calc_flag = 0, if not then always=1. Eg employee1 was from 2023/01/05 till 2023/01/12 on vacation. So all his invoices must be calc_flag=0 for this time.

How to create the sql query in mssql for this topic?

Thanks for any advice.

I already tried to check the dateframes but if there are several entries in vacation table, I'm not sure how to handle it.

Answer 1

One way to do this is a LEFT JOIN to check for existance. Perhaps you need to tweak the < or > depening if you would like to include the Begin and or End date.

SELECT i.InvNo,
       i.emp_ID,
       i.InvDate,
       i.calc_flag ,
       CASE WHEN v.Emp_ID IS NOT NULL THEN 0 ELSE 1 END AS calc_flage
FROM dbo.invoices AS i
LEFT JOIN dbo.vacation AS v ON v.Emp_ID = i.emp_ID AND v.[Begin] < i.InvDate AND v.[End] > i.InvDate