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Arithmetic Expressions (XQuery)

  • บทความ

Applies to: SQL Server

All arithmetic operators are supported, except for idiv. The following examples illustrate the basic use of arithmetic operators:

DECLARE @x xml  
SET @x=''  
SELECT @x.query('2 div 2')  
SELECT @x.query('2 * 2')

Because idiv is not supported, a solution is to use the xs:integer() constructor:

DECLARE @x xml  
SET @x=''  
-- Following will not work  
-- SELECT @x.query('2 idiv 2')  
-- Workaround   
SELECT @x.query('xs:integer(2 div 3)')

The resulting type from an arithmetic operator is based on the types of the input values. If the operands are different types, either one or both when required will be cast to a common primitive base type according to the type hierarchy. For information about type hierarchy, see Type Casting Rules in XQuery.

Numeric type promotion occurs if the two operations are different numeric base types. For example, adding an xs:decimal to an xs:double would first change the decimal value to a double . Next, addition would be performed that would result in a double value.

Untyped atomic values are cast to the other operand's numeric base type, or to xs:double if the other operand is also untyped.

Implementation Limitations

These are the limitations:

  • Arguments for the arithmetic operators must be of numeric type or untypedAtomic.

  • Operations on xs:integer values result in a value of type xs:decimal instead of xs:integer.