Dates Validation for Overlapping & Gaps (Leo asked)

[Leo]

Hi there,
I need to have a table to keep employees salaries, in which each employee
may have many different salaries on different ranges of dates, with fields of
EmployeeID , StartDate, EndDate, Salary Amount. For example employee A can
have a 2000 $ monthly salary from Jan 1st to Apr 30th , but 2500$ from May
1st to Dec 31st.
Data entry could be though a form or directly from table, but there must be
a control or constrain over validity of date ranges (the span between
StartDate and EndDate) in a way that no two records overlaps each other for
the same employee and also no gap between entries. For example if Employee A
receive a salary from Jan 1st to Mar 3oth , then the same employee can not
have a record of salary for Feb 1st to Apr 30th (overlapping) or Jun 1st to
Dec 31st (leave a gap).
How can I impose such a control for date validation??
I appreciate your help.

 

[Stefan Hoffmann]

hi Leo,

Data entry could be though a form or directly from table, but there must be
a control or constrain over validity of date ranges (the span between
StartDate and EndDate) in a way that no two records overlaps each other for
the same employee and also no gap between entries.

If the constraint 'no gap' is a necessary, significant business rule
then the solution is quite simple:

Use no EndDate. Store only the employee's ID, the salary and the start
date. The end date is determined by either the next records start date,
or by an external date reflecting the employee's state - fired at.

mfG
--> stefan <--

 

[SQL Superfast]

you can find sql query for the same at www.sqlsuperfast.com