Value Expression

A value expression can consist of the following items:

• Column Identifiers
• Functions
• Literals (For example, 1234, 'somestring')
• Expressions (For example, x+y, x AND y)

A value expression can be given a label to use when accessing the data for each column in a row of the query results as shown in the following example:

SELECT col1 AS c1 FROM mytable

If a value expression is not given a label, the entire string used to specify the value expression is used as the label as shown in the following example:

SELECT col1, col2 + col3, ‘row totals’ FROM mytable

To access the columns in the rows of the query result for the SELECT statement above, the following labels would be used:

• 'col1'
• 'col2 + col3'
• 'row totals'

For more information about expressions, see SQL Expressions.