Warning console : Each child in a list should have a unique “key” prop in table in code react.js

I want to correct the warning “Each child in a list should have a unique” key “prop” in the console. I tried adding the props “rowkey”, “key” in the but the problem still exists.

//***************************** Code ********************************//
class TableOfState extends React.Component {
render() {
const states = this.props.statesList;
const columns = [
//**************** I'm trying to add a column "id" *************************//
{
dataIndex: 'id',
key: 'id',
},
{
title: 'name',
dataIndex: 'name',
key: 'name',
},
{
title: 'Color',
dataIndex: 'color',
key: 'color',
},
];
return (
<div>
<Widget>
  <Row>
      <Table
    //******************* The two solutions that I tried *******************//
        // key={states.id}
        // id={states.id}
        // rowkey={states.idDept}
        dataSource={states}
        columns={columns}
        pagination={true}
        className="gx-table-responsive"
        style={{ width: "100%" }}
      />

       </Row>
    </Widget>
  </div>
)
}
}

Here is the warning on the console::

Answer

You need to add ‘key’ prop with unique value to all your data items

const dataSource = [
  {
    key: '1',
    id: 1,
    name: 'Mike',
    age: 32,
    address: '10 Downing Street',
  },
  {
    key: '2',
    id: 2,
    name: 'John',
    age: 42,
    address: '10 Downing Street',
  },
];

or if your items already have unique key (e.g. ‘id’), then specify it for Table component via rowKey prop:

<Table dataSource={dataSource} rowKey="id" ... />;