Basics

Database Management Systems

  • MySQL: run on servers separate from those running a website
  • PostgreSQL: run on servers separate from those running a website
  • SQLite: a lighter-weight system that can store all of its data in a single file

Column Types

  • TEXT: For strings of text (Ex. a person’s name) NUMERIC: A more general form of numeric data (Ex. A date or boolean value)
  • INTEGER: Any non-decimal number (Ex. a person’s age)
  • REAL: Any real number (Ex. a person’s weight)
  • BLOB (Binary Large Object): Any other binary data that we may want to store in our database (Ex. an image)

Constraints

  • CHECK: Makes sure certain constraints are met before allowing a row to be added/modified
  • DEFAULT: Provides a default value if no value is given
  • NOT NULL: Makes sure a value is provided
  • PRIMARY KEY: Indicates this is the pimary way of searching for a row in the database
  • UNIQUE: Ensures that no two rows have the same value in that column.