As I said, if the test has only one sample, no need for child table - 1 test, 1 sample, 1 table. However, doesn't matter how many samples if you have a child table, the primary/foreign keys would be as you have for Test3 and ResultT3.



I also maintain a database for a laboratory and have similar structure. We have over a hundred tests and so I have a table for each test number for details and results. Results are not in child tables although in some cases probably should be to comply with normalization principle but I choose not to go this additional step in normalization of data. Project can be downloaded from http://www.box.net/shared/r8nea07sng