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Contents > Definition of own types > Limiting the number of decimal places

Limiting the number of decimal places

  1. XML Schema
  2. Relax NG
XML Schema keys: restriction, base, decimal, minExclusive, fractionDigits
Relax NG keys: data, type, param

1. XML Schema

The element "A" represents your salary - it must be positive number and it must be rounded to two decimal places. We will define our custom type "Salary" using "minExclusive" and "fractionDigits" elements. The element "A" must be of that type.

Valid document


<A xsi:noNamespaceSchemaLocation="correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >1000.00</A>

Invalid document
Your salary can't be negative :-)


<A xsi:noNamespaceSchemaLocation="correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >-1000.00</A>

Invalid document
There are too many decimal places.


<A xsi:noNamespaceSchemaLocation="correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >999.9999</A>

Correct XML Schema (correct_0.xsd)


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" >

  <xsd:element name="A" type="Salary"/>

  <xsd:simpleType name="Salary">
    <xsd:restriction base="xsd:decimal">
      <xsd:minExclusive value="0"/>
      <xsd:fractionDigits value="2"/>
    </xsd:restriction>
  </xsd:simpleType>
</xsd:schema>

2. Relax NG

The element "A" must be positive number and it must be rounded to two decimal places. We will use the "decimal" datatype from XML Schemas and restrict it using the "fractionDigits" and "minExclusive" parameters (facets).

Valid document


<A xsi:noNamespaceSchemaLocation="correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >1000.25</A>

Valid document
This is valid too, because the number of decimal places must be less than or equal to 2.


<A xsi:noNamespaceSchemaLocation="correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >1000.0</A>

Invalid document
Your salary can't be negative :-)


<A xmlns="">-1000.00</A>

Invalid document
There are too many decimal places.


<A xmlns="">999.9999</A>

Correct Relax NG schema (correctRelax_0.rng)


<grammar datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes" xmlns="http://relaxng.org/ns/structure/1.0" >

  <start>
    <element>
      <name ns="">A</name>
      <ref name="Salary"/>
    </element>
  </start>

  <define name="Salary">
    <data type="decimal">
      <param name="minExclusive">0</param>
      <param name="fractionDigits">2</param>
    </data>
  </define>
</grammar>