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Learn about designing databases for biological research, including keys, SQL, relationships, naming conventions, data types, normalization, and database planning. Explore examples and exercises that cover species, location, habitat, visits, surveys, and more.
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Designing Databases for Biological Research Brian R. Mitchell Fall 2006
Introduction • Participants • Syllabus • Website: http://www.uvm.edu/~bmitchel/databases.html • Database options at UVM
What is a Database? • Definition • Keys • Structured Query Language (SQL) • Relationships
Relationships • One-to-one Technicians Contact_Info Amy Amy’s address Joe Joe’s Address Fred Fred’s Address
Relationships • One-to-many Site Count_Data 286 (+ site fields) 286 (species 1) 286 (species 2) 286 (species 3)
Relationships • Many-to-many Students Classes Ralph BIO 165 Susan NR 385 ?
Relationships • Many-to-many Students Classes Ralph BIO 165 Susan NR 385 Schedule Student & Class
Naming Conventions • Keep it short • Make it meaningful • No spaces – use underscores “_” • Avoid @#%$*& special characters • Be consistent
Naming Fields • Be specific • One piece of information per field • No calculated fields • Identify your keys
Naming Objects • Conventional abbreviations for objects: • Tables • tbl = data table • tlu = lookup table • xref = linking table • Queries = qry • Forms • frm = form • frm_sub or fsub = subform • Reports • rpt = report • rpt_sub or rsub = subreport • Pages = pag (not widely used) • Macros = mac (not widely used) • Modules = mod
Avoid Reserved Words avg key property count max section currency memo set date min sum desc name time exists number type group order value index percent year
Data Types • AutoNumber • Currency • Date/Time • Hyperlink • Memo • Number • OLE • Text • Yes/No
Database Design • Single Database or Front End / Back End? • Normalization
Database Design • Non-normalized Spreadsheet-style Site Date Observer Bird 24 7/1/04 BRM BTBW 24 7/1/04 BRM OVEN 24 7/1/04 BRM YBSA
Database Design • First Normal Form (1NF) Each field contains one value NO YES Coordinates UTM_E & UTM_N Birds seen Separate table
Database Design • Second Normal Form (2NF) If you have a composite key, no data relates to one of the keys Example from Northwind database
Database Design • Third Normal Form (3NF) Information in the table must not be related to a non-key field Example from Northwind database
Database Design • Plan your database • Why bother? • Iterative process • Tables • Relationships • Fields • Rules
Exercise Tables Fields Species Species_ID, Common, Sci Location Habitat, Coordinate Visit Time, Weather, Date Survey Minute, species, vis/aud Multiple visits to each location 10 minute count during each visit: listens for each individual of each species that can see or hear, records species, minute during count, visual/auditory