I am working on an attendance/overtime module for a schedule web app. The idea is that there is a table in MySQL of shifts, each shift having a start and end time. The manager will choose a shift and make an entry into the attendance table specifying whether the employee was early/late/left early/worked overtime. That entry in the attendance table is keyed to the shifts ID # (which is just an enumerated key).
But if someone comes in on their day off, there is no shift to key it to. What is a good system to use for those keys? Ccan I set up a conditional enumeration? And how do I avoid the risk of overlap with a shift ID? Adding the overtime shift back into the original schedule DB is not an option.
Similar to your previous question, if there is no data, then NULL is appropriate. In this case the work isn’t attached to a particular shift so what else can you put there? And again the status should reflect this.