Create XSD file from XML file

There are many tools to generate XSD from XML file, but I am using here trang.

STEP 1: First download trang from here (choose trang-20030619.zip)
STEP 2: Unzip this file at any location say C:\jar\trang-20030619\trang-20030619
STEP 3: Create one xml file at any location say C:\workspaceAll\XSD\XMLTOXSD\src\StudentInfo.xml

StudentInfo.xml

<?xml version="1.0" encoding="UTF-8"?><StudentData xmlns="http://mycompany.com/hr/schemas;
<Student>
<RollNo>110</RollNo>
<FirstName>Ultimate</FirstName>
<LastName>Answer</LastName>
<ContactNo>9900990011</ContactNo>
</Student>
<Hostel>
<Name>Ganga</Name>
<Location>South Corner</Location>
<RoomNo>20</RoomNo>
</Hostel>
</StudentData>

STEP 4: Now use this command

C:\workspaceAll\XSD\XMLTOXSD\src>java -jar C:\jar\trang-20030619\trang-20030619\trang.jar StudentInfo.xml StudentRecord.xsd

STEP 5: Now you will get StudentRecord.xsd at C:\workspaceAll\XSD\XMLTOXSD\src location. And StudentRecord.xsd will like this

<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="http://mycompany.com/hr/schemas" xmlns:schemas="http://mycompany.com/hr/schemas;
<xs:element name="StudentData">
<xs:complexType>
<xs:sequence>
<xs:element ref="schemas:Student"/>
<xs:element ref="schemas:Hostel"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="Student">
<xs:complexType>
<xs:sequence>
<xs:element ref="schemas:RollNo"/>
<xs:element ref="schemas:FirstName"/>
<xs:element ref="schemas:LastName"/>
<xs:element ref="schemas:ContactNo"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="RollNo" type="xs:integer"/>
<xs:element name="FirstName" type="xs:NCName"/>
<xs:element name="LastName" type="xs:NCName"/>
<xs:element name="ContactNo" type="xs:integer"/>
<xs:element name="Hostel">
<xs:complexType>
<xs:sequence>
<xs:element ref="schemas:Name"/>
<xs:element ref="schemas:Location"/>
<xs:element ref="schemas:RoomNo"/>
</xs:sequence>

</xs:complexType>
</xs:element> <xs:element name="Name" type="xs:NCName"/>
<xs:element name="Location" type="xs:string"/>
<xs:element name="RoomNo" type="xs:integer"/>
</xs:schema>

It is very easy :)

IMP: If you want to develop any XSD file, so it would be better idea that first write XML file then using trang utility create XSD file. For example, I have below xml (persons.xml)
<?xml version="1.0" ?>
<information>
<person id="1">
<name>Binod</name>
<age>24</age>
<gender>Male</gender>
</person>

<person id="2">
<name>Pramod</name>
<age>22</age>
<gender>Male</gender>
</person>

<person id="3">
<name>Swetha</name>
<age>19</age>
<gender>Female</gender>
</person>
</information>
Now use the trang command and get your XSD file. I kind suggestion, never dig your head to develop XSD file by using XSD tags. Always use trang command. :)
java -jar c:\jar\trang-20030619\trang-20030619\trang.jar persons.xml personsFormat.xsd
personsFormat.xsd

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
<xs:element name="information">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded" ref="person"/>
</xs:sequence>
</xs:complexType>

</xs:element>
<xs:element name="person">
<xs:complexType>
<xs:sequence>
<xs:element ref="name"/>
<xs:element ref="age"/>
<xs:element ref="gender"/>
</xs:sequence>
<xs:attribute name="id" use="required" type="xs:integer"/>
</xs:complexType>
</xs:element>
<xs:element name="name" type="xs:NCName"/>
<xs:element name="age" type="xs:integer"/>
<xs:element name="gender" type="xs:NCName"/>
</xs:schema>