Difference between dtd and xsd
6 likes30,879 views
DTD and XSD are both used to define the structure and legal elements of an XML document, but XSD provides more robust validation capabilities. DTD has limitations in that it only supports validation of the root element, lacks namespaces and data types, and is weakly typed. In contrast, XSD supports validation of any element, uses namespaces, provides primitive and custom data types with restrictions, and is strongly typed. While DTD is suitable for small XML data, XSD is better suited for large XML documents like those used in web services and datasets due to its stronger validation features.
Difference between dtd and xsd
- 1. Difference between DTD and XSD S.No DTD XSD 1 Abbreviation: Abbreviation: DTD stands for Document Type XSD stands for Xml Schema Definition Definition 2 Markup validation: Markup validation: Can specify only the root element Any global element can be root. No in the instance document. No ambiguous content support. ambiguous content support. 3 Namespace support : Namespace support : DTD does not support namespace XSD uses its own set of namespaces instead it has its own set of and elements for defining the schema. keywords for defining a schema example: !DOCTYPE for root tag !ELEMENT for an element !ATTLIST for an attribute !ENTITY for defining variables. 4 Code reuse: Code reuse: Poorly supported. Can use Can reuse definitions using named parameter entities. types. 5 Datatype Support : Datatype Support : No real datatype support. DTD Provides flexible set of datatypes. has only #PCDATA as the data type for the elements.(it is used 1. primitive / fundamental data types: for string datatype) string,decimal,float,boolean 2. Custom Data types i. complex type : a data type that contains child elements or attributes and also the mixed contents ii. simple type : a data type that contains only values. Provides multi-field key cross references. No co-occurrence constraints. 6 Datatype Validation: Datatype Validation: In DTD, no such restrictions XSD allows us to specify restriction
- 2. on data . Example: <price></price> tag. we can write only digits here. 7 Uses: Uses: DTD is more suitable for small XSD is used in large XML Data ex: XML Data ADO.NET DataSets, Web Services. ex:bookname,companyname etc. 8 Strongly / Weakly typed: Strongly / Weakly typed: DTD is weaky typed. XML Schema is strongly typed. DTD lacks strong typing An XML Schema can define the data capabilities, and has no way of type of certain elements, and even validating the content to data constrain it to within specific lengths types. or values. This ability ensures that the data stored in the XML document is accurate. 9 Provisions of Inline Definitions: Provisions of Inline Definitions: DTD allows inline definitions. XML Schema does not allow inline definitions This is good when working with small files, as it allows us to contain both the content and the schema within the same document, but when it comes to larger documents, this can be a disadvantage, as we pull content every time we retrieve the schema. This can lead to serious overhead that can degrade performance. And, further updates on difference between questions and answers, please visit my blog @ http://onlydifferencefaqs.blogspot.in/