how to update data in same table in sql? : I want to update user_placement_id corresponding user_placement collumn that give below username . i want to update user_placement_id with the user_placement that reffer in username.

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    table

    tr{
    text-align:center}

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    <h1>userbase table and primary key is 'user_id'</h1>
    <table border="1">
        <tr>
            <th>user_id</th>
            <th>user_name</th>
            <th>user_placement</th>
            <th>user_placement_id</th>
        </tr>

        <tr>
            <td>1</td>
            <td>jone1</td>
            <td>jone2</td>
            <td>0</td>
        </tr>
        <tr>
            <td>2</td>
            <td>jone2</td>
            <td>jone1</td>
            <td>0</td>
        </tr>
        <tr>
            <td>3</td>
            <td>jone3</td>
            <td>jone2</td>
            <td>0</td>
        </tr>
        <tr>
            <td>4</td>
            <td>jone4</td>
            <td>jone3</td>
            <td>0</td>
        </tr>
        <tr>
            <td>5</td>
            <td>jone5</td>
            <td>jone4</td>
            <td>0</td>
        </tr>
    </table>

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