Simple use of SELECT and WHERE

• attribute-list
• • This is usually a comma separated list of attributes (field names)
  • Expressions involving these attributes may be used. The normal mathematical operators +, -, *, / may be used on numeric values. String values may be concatenated using ||
  • To select all attributes use *
  • The attributes in this case are: name, region, area, population and gdp
• table-name
  • In these examples the table is always bbc.
• condition
• • This is a boolean expression which each row must satisfy.
  • Operators which may be used include AND, OR, NOT, >, >=, =, <, <=
  • The LIKE operator permits strings to be compared using 'wild cards'. The symbols _ and % are used to represent a single character or a sequence of characters. Note that MS Access SQL uses ? and * instead of _ and % .
  • The IN operator allows an item to be tested against a list of values.
  • There is a BETWEEN operator for checking ranges.

A common mistake made with boolean expressions

Boolean expressions often read like "normal" English however the syntax is not as rich. For example we might say name equals 'France' or 'Germany' however the corresponding boolean expression is name='France' OR name='Germany'