title: Unable to load data for nested table dynamically
body: <p>I have created a table using component <code>nztable</code> from ``ng-zorro`. That table contains a nested table where I want to load data dynamically(REST service call) on click of the expand icon. </p>
  
  <p>I am able to load the data in the nested table but when I expand next row, it is overriding data in the first row with the new result. </p>
  
  <p>As nested table creation is in the loop(ngfor), I am unable to control the data binding to a specific row. </p>
  
  <pre><code>&lt;nz-table #nestedTable [nzData]="displayData" [nzPageSize]="10"&gt;
      &lt;thead colspan="5"&gt;
      &lt;tr&gt;
        &lt;th nzWidth="4%"nzShowExpand&gt;&lt;/th&gt;
        &lt;th nzWidth="12%"&gt;Id&lt;/th&gt;
        &lt;th nzWidth="10%"&gt;Start Time&lt;/th&gt;
        &lt;th nzWidth="10%"&gt;End Time&lt;/th&gt;
        &lt;th nzWidth="10%"&gt;Status&lt;/th&gt;
      &lt;/tr&gt;
      &lt;/thead&gt;
      &lt;tbody&gt;
      &lt;ng-template ngFor let-data [ngForOf]="nestedTable.data"&gt;
        &lt;tr&gt;
          &lt;td nzShowExpand [(nzExpand)]="data.expand" (click)="getDetails(data)"&gt;&lt;/td&gt;
          &lt;td &gt;{{data.Id}}&lt;/td&gt;
          &lt;td&gt;{{data.startTime}}&lt;/td&gt;
          &lt;td&gt;{{data.endTime}}&lt;/td&gt;
          &lt;td&gt;{{data.status}}&lt;/td&gt;
        &lt;/tr&gt;
        &lt;tr [nzExpand]="data.expand"&gt;
          &lt;td&gt;&lt;nz-spin  *ngIf="isEventLoading"&gt;&lt;/nz-spin&gt;&lt;/td&gt;
          &lt;td colspan="9"&gt;
            &lt;nz-table #innerTable [nzData]="innerTableData" nzSize="middle" [nzShowPagination]="false"&gt;
      &lt;thead&gt;
      &lt;tr&gt;
        &lt;th&gt;E ID&lt;/th&gt;
        &lt;th&gt;S ID&lt;/th&gt;
        &lt;th&gt;E Type&lt;/th&gt;
      &lt;/tr&gt;
      &lt;/thead&gt;
      &lt;tbody&gt;
      &lt;tr *ngFor="let data of innerTable.data"&gt;
        &lt;td&gt;{{data.eID}}&lt;/td&gt;
        &lt;td&gt;{{data.sID}}&lt;/td&gt;
        &lt;td&gt;{{data.eType}}&lt;/td&gt;
      &lt;/tr&gt;
      &lt;/tbody&gt;
      &lt;/nz-table&gt;
  </code></pre>