Character data not allowed by content model - XSD

Question

Trying to check a small xml, I get the following error: no character data is allowed by the content model.

This is my xml example:

<?xml version="1.0" encoding="UTF-8"?>
<plats xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="1_e.xsd">
    <primer codi='3'>Caldo de verdures</primer>
    <segon codi='4'>Pollastre al forn</segon>
    <primer codi='7'>Spaguettis</primer>
    <segon codi='12'>Llus a la planxa</segon>
</plats>

And this is my xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">

<xs:complexType name="t_primer">
  <xs:choice>
    <xs:element name="primer" type="xs:string" />
  </xs:choice>
  <xs:attribute name="codi" type="xs:string" />
</xs:complexType>

<xs:complexType name="t_segon">
  <xs:choice>
    <xs:element name="segon" type="xs:string" />
  </xs:choice>
  <xs:attribute name="codi" type="xs:string" />
</xs:complexType>

  <xs:element name="plats">
    <xs:complexType>
     <xs:choice>
      <xs:sequence>
        <xs:element name="primer" type="t_primer" />
      </xs:sequence>
      <xs:sequence>
        <xs:element name="segon" type="t_segon" />
      </xs:sequence>
     </xs:choice>
    </xs:complexType>
  </xs:element>
</xs:schema>

I can not find where I am wrong, and the code looks good ...

Answer 1

Solved the problem:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">

<xs:complexType name="t_primer">
  <xs:simpleContent>
    <xs:extension base="xs:string">
      <xs:attribute name="codi" type="xs:string"/>
    </xs:extension>
  </xs:simpleContent>
</xs:complexType>

<xs:complexType name="t_segon">
  <xs:simpleContent>
    <xs:extension base="xs:string">
      <xs:attribute name="codi" type="xs:string"/>
    </xs:extension>
  </xs:simpleContent>
</xs:complexType>

  <xs:element name="plats">
    <xs:complexType>
    <xs:choice minOccurs="0" maxOccurs="unbounded">
      <xs:element name="primer" type="t_primer" />
      <xs:element name="segon" type="t_segon" />
    </xs:choice>
    </xs:complexType>
  </xs:element>
</xs:schema>