org.postgresql.util.PSQLException:在此结果集中找不到列名 usuario [英] org.postgresql.util.PSQLException: The column name usuario was not found in this ResultSet

问题描述

我收到以下错误:org.postgresql.util.PSQLException: The column name usuario was not found in this ResultSet.

I am getting the following error: org.postgresql.util.PSQLException: The column name usuario was not found in this ResultSet.

但是，我在适当的类中正确声明了以下列 usuario！

However, I have the following column usuario declared properly in the appropriate classes!

UsuariosGruposDAO.class

UsuariosGruposDAO.class

public Object objectFactory(ResultSet rs) {
        try {
            UsuariosGrupos usergroup = new UsuariosGrupos(rs.getString("usuario"), rs.getString("grupo"));
            return usergroup;
        } catch (SQLException e) {
            e.printStackTrace();
            // retorno do método
            return null;
        }
    }

UsuariosGrupos.class

UsuariosGrupos.class

public class UsuariosGrupos {

    private String usuario;
    private String grupo;

    public UsuariosGrupos() {
    }

    public UsuariosGrupos(String usuario, String grupo) {
        this.usuario = usuario;
        this.grupo = grupo;
    }

错误出现在以下行:

       ugList.add((UsuariosGrupos) objectFactory(rs));  

我的列表方法:

List<UsuariosGrupos> ugList = null;
    try {
        //Conecta no banco
        conn.conectar();
        //Prepara o preparedStatment
        stmt = (PreparedStatement) conn.getPreparedStatement("SELECT * from usuarios_grupos");
        //Executa a instrucao SQL
        ResultSet rs = stmt.executeQuery();
        ugList = new ArrayList<UsuariosGrupos>();
        //Enquanto ouver resultSet
        while (rs.next()) {
            ugList.add((UsuariosGrupos) objectFactory(rs));
        }
        System.out.println("################################UsuariosGrupos OK################################");
    } catch (SQLException e) {
        System.out.println("################################UsuariosGrupos Falhou################################");
        e.printStackTrace();
    } finally {
        conn.desconectar();
    }
    return ugList;
}

奇怪的是，当我单独测试我的列表时，数据表显示了适当的结果.但是，当我运行整个应用程序时，没有任何显示，并且出现错误，指出在结果集中找不到 usuario 列.有什么建议吗?

The weird thing is when I test my List separately, the datatable displays the appropriate results. However, when I run my entire application, nothing shows up, and I get that error stating the column usuario cannot be found in the resultset. Any suggestions?

该表有两个字段:

Usuarios | Grupos

admin        2
admin        3

当我分离我的 jsf 代码时它显示良好，但当我将它放在一个 JSF 文件中时不显示数据.

It displays fine, when I separate my jsf code, but doesn't display the data when I have it on one JSF file.

推荐答案

您的表转储显示该字段为Usarios"，但您正在执行 rs.getString("usuario").不应该是下面这样吗?

Your table dump shows the field as "Usarios" but you are doing a rs.getString("usuario"). Shouldln't that be the following?

rs.getString("usuarios")

如果这不起作用，那么我建议调试您的代码，在 getString 行上放置一个断点并查看 ResultSet 以查看字段名称是什么

If that doesn't work then I would recommend debugging your code, putting a breakpoint on the getString line and looking at the ResultSet to see what the field names are there.

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