Field-Expressions

Field-expressions are a combination of symbols and functions that Log Parser evaluates to obtain a single data value. These are the basic arguments of the SELECT, USING, WHERE, GROUP BY, HAVING, and ORDER BY clauses.

Field-expressions can be divided conceptually into two groups:

• Derived field-expressions: functions or aggregate functions having other field-expressions as arguments;
• Basic field-expressions: constant values (including functions with no arguments), names of input record fields, or aliases defined in the SELECT or USING clauses.

Examples:

A. Basic field-expressions

The SELECT clause in the following example query specifies "basic" field-expressions only:

SELECT 'Event ID:', EventID, SYSTEM_TIMESTAMP()
FROM System

B. Derived field-expressions

The SELECT clause in the following example query specifies "derived" field-expressions only:

SELECT TO_UPPERCASE(cs-uri-stem), SUM(sc-bytes)
FROM \MyLogs\ex042805.log
GROUP BY TO_UPPERCASE(cs-uri-stem)

See also:

Basics of a Query

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