title: Customising column sort order in v-data-table
body: <p>I have an array auditResult(the data came from response.data.data) that have value like
  -internalID
  -fieldName
  -OldValue
  -NewValue</p>
  
  <p>I have a table </p>
  
  <pre class="lang-html prettyprint-override"><code>  &lt;v-data-table :items="auditResults" :headers="headers" class="searchable sortable"&gt;
      &lt;template v-slot:items="props"&gt;
        &lt;td&gt;{{ getCodeValue(props.item.codeid) }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.fieldname }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.oldvalue }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.newvalue }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.requestedwhen | formatDate }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.changedappliedwhen | formatDate }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.requestedby }}&lt;/td&gt;
        &lt;td&gt;{{ props.item.reasonforchange }}&lt;/td&gt;
      &lt;/template&gt;
      &lt;template v-slot:no-results&gt;
        &lt;v-alert :value="true" color="error" icon="warning"&gt;Found no results.&lt;/v-alert&gt;
      &lt;/template&gt;
    &lt;/v-data-table&gt;
  </code></pre>
  
  <p>Now I have a method called getCodeValue where the internalID is compared to Code to get the Code Value
  here is the code:</p>
  
  <pre class="lang-js prettyprint-override"><code>getCodeValue(codeid) {
    let codeFound = this.codeResults.find(m =&gt; m.internalid == codeid);
    if (codeFound) {
      this.auditResults.codeid = codeFound.code;
      return this.auditResults.codeid;
    }
    return "Code not found";
  }
  </code></pre>
  
  <p>Now my problem is instead the Code will be sorted the table is using the internalID to sort it. Reason being is the table item is auditResult.</p>
  
  <p>How can I achieve that the table should sort the Code from getCodeValue method and not the internalID from auditResult.</p>