org.hibernate.exception.SQLGrammarException: could not extract ResultSet のエラーについて

前提・実現したいこと

ページを表示させたいのですが、表示されずエラーとなってしまいます。

発生している問題・エラーメッセージ

例外
javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not extract ResultSet
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:149)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157)
	org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1423)
	org.hibernate.query.Query.getResultList(Query.java:146)
	controllers.employees.EmployeeIndexServlet.doGet(EmployeeIndexServlet.java:43)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	filters.EncodingFilter.doFilter(EncodingFilter.java:42)
原因
org.hibernate.exception.SQLGrammarException: could not extract ResultSet
	org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:63)
	org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
	org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
	org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
	org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:69)
	org.hibernate.loader.Loader.getResultSet(Loader.java:2168)
	org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1931)
	org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1893)
	org.hibernate.loader.Loader.doQuery(Loader.java:938)
	org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341)
	org.hibernate.loader.Loader.doList(Loader.java:2692)
	org.hibernate.loader.Loader.doList(Loader.java:2675)
	org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2507)
	org.hibernate.loader.Loader.list(Loader.java:2502)
	org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:502)
	org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:392)
	org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)
	org.hibernate.internal.SessionImpl.list(SessionImpl.java:1490)
	org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1445)
	org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1414)
	org.hibernate.query.Query.getResultList(Query.java:146)
	controllers.employees.EmployeeIndexServlet.doGet(EmployeeIndexServlet.java:43)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	filters.EncodingFilter.doFilter(EncodingFilter.java:42)
原因

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'employee0_.admin_flg' in 'field list'
	sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
	com.mysql.jdbc.Util.getInstance(Util.java:408)
	com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
	com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973)
	com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909)
	com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527)
	com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
	com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2484)
	com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
	com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1966)
	org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:60)
	org.hibernate.loader.Loader.getResultSet(Loader.java:2168)
	org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1931)
	org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1893)
	org.hibernate.loader.Loader.doQuery(Loader.java:938)
	org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341)
	org.hibernate.loader.Loader.doList(Loader.java:2692)
	org.hibernate.loader.Loader.doList(Loader.java:2675)
	org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2507)
	org.hibernate.loader.Loader.list(Loader.java:2502)
	org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:502)
	org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:392)
	org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)
	org.hibernate.internal.SessionImpl.list(SessionImpl.java:1490)
	org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1445)
	org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1414)
	org.hibernate.query.Query.getResultList(Query.java:146)
	controllers.employees.EmployeeIndexServlet.doGet(EmployeeIndexServlet.java:43)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	filters.EncodingFilter.doFilter(EncodingFilter.java:42)

該当のソースコード

        List<Employee> employees = em.createNamedQuery("getAllEmployees", Employee.class).setFirstResult(15 * (page - 1)).setMaxResults(15).getResultList();

@WebServlet("/employees/index")
public class EmployeeIndexServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public EmployeeIndexServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        EntityManager em = DBUtil.createEntityManager();

        int page = 1;
        try{
            page = Integer.parseInt(request.getParameter("page"));

        } catch(NumberFormatException e) {}
        List<Employee> employees = em.createNamedQuery("getAllEmployees", Employee.class).setFirstResult(15 * (page - 1)).setMaxResults(15).getResultList();

        long employees_count = (long)em.createNamedQuery("getEmployeesCount", Long.class).getSingleResult();

        em.close();

        request.setAttribute("employees", employees);
        request.setAttribute("employees_count", employees_count);
        request.setAttribute("page", page);
        if(request.getSession().getAttribute("flush") != null){
            request.setAttribute("flush", request.getSession().getAttribute("flush"));
            request.getSession().removeAttribute("flush");
        }

        RequestDispatcher rd = request.getRequestDispatcher("/WEB-INF/views/employees/index.jsp");
        rd.forward(request, response);
    }

}