Sample Schema for Tracking Chemical Samples

These are the operations that are required by users of this compound tracking system  

These are the questions that need to be routinely answered by users of this schema  

These are the items that need to be stored in the schema  

The next table to consider is the checkout table. When a sample is taken, either the parent sample or a subsample, data are recorded in the checkout table. A sample id is recorded, the checked out date is recorded, a valid location id from the alocation table is chosen, and a valid chemist id from the chemist table is chosen. Note that 

The purpose of the compos it ion table is to provide the ability to store the information that a sample consists of one or many compounds. There might be many rows in composition, each with the same sample id and different compound ids. Or there may be a single entry in the composition table indicating that a sample contains only one compound. Finally, there may be no entry in composition for a sample id indicating that the sample is of unknown composition. 

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