Databases

Databases

1. Data Structure Table

2. Primary Key

   • Unique to one person ONLY

3. Splitting up the data

   • Can't just have one massive table
   • Takes up too much space.
   • Normalisation
     • From a massive group to split it up into smaller group which is more manageable

4. Relationships

   • One to One Relationship
   • One to many
   • Many to Many

5. Foreign Key

   • The foreign key is like this.
     • One tutor group can have MANY students.

6. QUERIES

   • SQL
     • SQL is a standardised method of interrogating a database regardless what software/platform you have used to create the database
     • Commands
       • Select
         • list the fields you want to displayed here.
       • From
         • List the table or tables the data will come from here
       • Where
         • List search criteria here
       • Order by
         • List field(s) you want the results sorted by here
     • Example
       • SELECT Details.ID, Details.[Student Name], Details.[Student Age],
       • A semi-colon will appear at the end of the last line of SQL Code.
     • New Data (Syntax)
       • Insert into
         • Table name (Fieldname, Fieldname, Fieldname)
         • Values
           • (value, value, value)
   • My Examples
     • SELECT Details.ID Details.[Student Name] Details.[Student Age] Details.[Hair Colour] Details.[Eye Colour]
       • FROM Details
         • WHERE (((Details.[Student Name]) = "ADAM") AND ((Details.[Eye Colour])= "Blue"))
           • ORDER BY

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