Artikel
05/23/2011

ceiling Function (XQuery)

Returns the smallest number without a fractional part and that is not less than the value of its argument. If the argument is an empty sequence, it returns the empty sequence.

Syntax

fn:ceiling ( $arg as numeric?) as numeric?

Arguments

$arg
Number to which the function is applied.

Remarks

If the type of $arg is one of the three numeric base types, xs:float, xs:double, or xs:decimal, the return type is the same as the $arg type.

If the type of $arg is a type that is derived from one of the numeric types, the return type is the base numeric type.

If the input to the fn:floor, fn:ceiling, or fn:round functions is xdt:untypedAtomic, it is implicitly cast to xs:double.

Any other type generates a static error.

Examples

This topic provides XQuery examples against XML instances that are stored in various xml type columns in the AdventureWorks2008R2 database. For an overview of each of these columns, see xml Data Type Representation in the AdventureWorks2008R2 Database.

A. Using the ceiling() XQuery function

For product model 7, this query returns a list of the work center locations in the manufacturing process of the product model. For each work center location, the query returns the location ID, labor hours, and lot size, if documented. The query uses the ceiling function to return the labor hours as values of type decimal.

SELECT ProductModelID, Instructions.query('
declare namespace AWMI="https://schemas.microsoft.com/sqlserver/2004/07/adventure-works/ProductModelManuInstructions"; 
     for $i in /AWMI:root/AWMI:Location
     return 
       <Location LocationID="{ $i/@LocationID }" 
                   LaborHrs="{ ceiling($i/@LaborHours) }" >
                    { 
                      $i/@LotSize
                    }  
       </Location>
') AS Result
FROM Production.ProductModel
WHERE ProductModelID=7

Note the following from the previous query:

The AWMI namespace prefix stands for Adventure Works Manufacturing Instructions. This prefix refers to the same namespace used in the document being queried.
Instructions is an xml type column. Therefore, the query() method (XML data type) is used to specify XQuery. The XQuery statement is specified as the argument to the query method.
for ... return is a loop construct. In the query, the for loop identifies a list of <Location> elements. For each work center location, the return statement in the for loop describes the XML to be generated:
- A <Location> element that has LocationID and LaborHrs attributes. The corresponding expression inside the braces ({ }) retrieves the required values from the document.
- The { $i/@LotSize } expression retrieves the LotSize attribute from the document, if present.
- This is the result:

ProductModelID Result  
-------------- ------------------------------------------------------
7      <Location LocationID="10" LaborHrs="3" LotSize="100"/>
       <Location LocationID="20" LaborHrs="2" LotSize="1"/>   
       <Location LocationID="30" LaborHrs="1" LotSize="1"/>   
       <Location LocationID="45" LaborHrs="1" LotSize="20"/>
       <Location LocationID="60" LaborHrs="3" LotSize="1"/>   
       <Location LocationID="60" LaborHrs="4" LotSize="1"/>

Implementation Limitations

These are the limitations:

The ceiling() function maps all integer values to xs:decimal.

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