Question

I’ve got a excel sheet that contains all the employees that have worked for my company and is still working for us. It’s a sheet of around 200 rows. Each row has basic info, like surname, name, position, qualification etc etc. 16 columns of basic info. Now, the tricky part is this. After the 16 columns, there are months (May-05 up to the present (Apr-12)). Under every month column, an employee either get’s a 0 (contract), 1 (permanent), 2 (contract-terminated) or 3 (student).

What would be the best way to do this? I was thinking of 4 tables (listed below), where the one table determines permanently terminated people (for the sake of knowing who was on what type of employment).

MySQL Table: hr_employees
|-----------------|-------|----|----|----|
| employee_number | name  | sur| etc| etc|
|-----------------|-------|----|----|----|
| 1               | Dave  | F  | xx | xx |
|-----------------|-------|----|----|----|

MySQL Table: hr_month
|----|--------|
| id | month  |
|----|--------|
| 1  | May-05 |
| 2  | Jun-05 |
|----|--------|

MySQL Table: hr_status
|----|------|------|--------|
| id | e_no | date | status |
|----|------|------|--------|
| 1  | 1    |  1   |   1    |
| 2  | 1    |  2   |   1    |
|----|------|------|--------|

MySQL Table: hr_terminated
|----|------|
| id | e_no |
|----|------|
| 1  | 1    |
| 2  | 1    |
|----|------|

I hope you guys understand what I want to achieve, otherwise, ask a question, and I’ll answer as best I can! 🙂

Thanks.

Answer 1

Here is a design that simplifies your data entry and is more relational database like and less Excel like, insofar as it’s normalized.

MySQL Table: hr_employee
|-----------------|-------|----|----|----| 
| employee_number | name  | sur| etc| etc| 
|-----------------|-------|----|----|----| 
| 1               | Dave  | F  | xx | xx | 
|-----------------|-------|----|----|----| 
| 2               | Bob   | M  | xx | xx | 
|-----------------|-------|----|----|----| 

MySQL Table: hr_employee_status
|-----------------|------------|------------|--------| 
| employee_number | from_date  | to_date    | status | 
|-----------------|------------|------------|--------| 
| 1               | 2005-05-01 | 2005-08-31 |   3    | 
|-----------------|------------|------------|--------| 
| 1               | 2006-05-01 | 2010-02-28 |   0    | 
|-----------------|------------|------------|--------| 
| 2               | 2010-03-01 | 9999-12-31 |   1    | 
|-----------------|------------|------------|--------| 

Here you can see that Dave was hired on as a student from May ’05 to August ’05, then he came back in May ’06 as a contract employee which he worked as until the end of February ’10. Then on March 1, 2010 Bob was hired as permanent employee and he is still working (max collating date means “until further notice”).

The great advantage of this design is that you only have to enter/edit data when something changes, not once a month for every employee that you have or have ever had. You can also see what your workforce looked like at any given date (not just by months!) with a very simple SQL query.