Professional Microsoft® SQL Server® Analysis Services 2008 with MDX

3.5. Operators

The MDX language, similar to other query languages such as SQL or other general-purpose programming languages, has several operators. An operator is a function that is used to perform a specific action, takes arguments, and returns a result. MDX has several types of operators including arithmetic operators, logical operators, and special MDX operators.

3.5.1. Arithmetic Operators

Regular arithmetic operators such as +, −, *, and / are available in MDX. Just as with other programming languages, these operators can be applied on two numbers. The + and − operators can also be used as unary operators on numbers. Unary operators, as the name indicates, are used with a single operand (single number) in MDX expressions such as + 100 or −100.

3.5.2. Set Operators

The +, −, and * operators, in addition to being arithmetic operators, are also used to perform operations on the MDX sets. The + operator returns the union of two sets, the − operator returns the difference of two sets, and the * operator returns the cross product of two sets. The cross product of two sets results in all possible combinations of the tuples in each set and helps in retrieving data in a matrix format. For example, if you have two sets, {Male, Female} and {2003, 2004, 2005}, the cross product, represented as {Male, Female} * {2003, 2004, 2005}, is {(Male,2003), (Male,2004), (Male,2005),(Female,2003),(Female,2004),(Female,2005)}. The following examples show MDX expressions that use the set operators: ...