Databases - Storing numerical value in VARCHAR datatype

Question

I am currently working on a project which requires me to store the hemoglobin level recorded as well as blood pressure, before a blood donation... something like '190/80'.. Should I store this in a Varchar as a string or as two separate values for example systolic (INT) 190, diastolic (INT) 80 ? Feedback appreciated

Answer 1

This is my feedback: I would use the two column approach, storing in separate colums systolic and diastolic values for each observation.

At the point of deploying data, or reporting, just concatenate.

The two column approach helps you on further reporting, you may be able to summarize data, say you need to average blood pressure of a population group, average data for a period of time, or under any given circumstances.

Answer 2

They should be two different numeric fields. Otherwise you cannot calculate statistics or change over time for each donor.