<sql:setDataSource var="ds" driver="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/Prodotti1" user="root" password="root"/>
<sql:query dataSource="${ds}" var="result">
    SELECT * from Producer;
</sql:query>

    <c:forEach var="row" items="${result.rows}">
          <option value='<c:out value="${row.producer_name}"/>'>
          <c:out value="${row.producer_name}"/></option>
    </c:forEach>

<s:select label="Producer"
    headerKey="-1" headerValue="--Select--"
    list=""
    name="" />

The requested list key '%{#result.row}' could not be resolved as a collection/array/map/enumeration/iterator type