WHERE Clause

The WHERE clause narrows the scope of a query. This clause contains a conditional expression, that can contain a property or key word, an operator, and a constant.

The syntax for a WHERE clause appended to a SELECT statement is as follows:

SELECT CIMinstance FROM CIMclass WHERE conditional_expression

The conditional_expression in the WHERE clause takes the following form:

 
property operator constant

The expression is composed of a property or key word, an operator, and a constant. You can append the WHERE clause to the SELECT statement using one of the following forms:

SELECT instance FROM class WHERE constant operator property

Valid WHERE clauses follow these rules:

• The value of the constant must be of the correct data type for the property.

• The operator must be a valid WQL operator.

• Either a property name or a constant must appear on either side of the operator in the WHERE clause.

• Arbitrary arithmetic expressions cannot be used. For example, the following query returns only instances of the Solaris_Printer class that represent a printer with ready status:

  SELECT * FROM Solaris_Printer WHERE Status = `ready'

• Multiple groups of properties, operators, and constants can be combined in a WHERE clause using logical operators and parenthetical expressions. Each group must be joined with the AND, OR, or NOT operators.

  The following example retrieves all instances of the Solaris_FileSystem class with the Name property set to either home or files:

  SELECT * FROM Solaris_FileSystem WHERE Name= `home' OR Name= `files'

  The following example retrieves disks named home and files only if the disks have a certain amount of available space remaining, and have Solaris platform file systems.

  SELECT * FROM Solaris_FileSystem WHERE (Name = `home' OR Name = `files') AND AvailableSpace > 2000000 AND FileSystem = `Solaris'

Standard WQL Operators for WHERE Clauses

You can use the following standard WQL operators for a binary expression in the WHERE clause of a SELECT statement.