Question

首先，抱歉我的英语不好。当我运行此方法时，它会抛出异常，并且它表示存在的列不存在，请查看该方法：

public Reprobacion obtenerReprobacion(int id){
        Reprobacion miRep = new Reprobacion();
        try{
            sql = "SELECT * FROM reprobacion WHERE idReprobacion = ?";
            st = conexion.prepareStatement(sql);
            st.setInt(1, id);
            rs = st.executeQuery();
            rs.beforeFirst();
            rs.next();

            miRep.setIdReprobacion(rs.getInt("IdReprobacion"));
            miRep.setIdCiclo(rs.getInt("IdCiclo"));
            miRep.setCiclo(obtenerCiclo(miRep.getIdCiclo()).getCiclo());
            miRep.setMateria(rs.getString("Materia"));
            miRep.setNota(rs.getFloat("Nota"));
            miRep.setDetalle(rs.getString("Detalle"));

        }catch(SQLException ex){
            ex.printStackTrace();
        }

        return miRep;
    }

它扔了：

java.sql.SQLException: Column 'Materia' not found.
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:910)
    at com.mysql.jdbc.ResultSet.findColumn(ResultSet.java:955)
    at com.mysql.jdbc.ResultSet.getString(ResultSet.java:5447)
    at org.apache.tomcat.dbcp.dbcp.DelegatingResultSet.getString(DelegatingResultSet.java:263)
    at org.apache.tomcat.dbcp.dbcp.DelegatingResultSet.getString(DelegatingResultSet.java:263)
    at org.ccgk.www.model.ReprobacionesModel.obtenerReprobacion(ReprobacionesModel.java:67)
    at org.ccgk.www.controller.ReprobacionesController.obtener(ReprobacionesController.java:186)
    at org.ccgk.www.controller.ReprobacionesController.processRequest(ReprobacionesController.java:52)
    at org.ccgk.www.controller.ReprobacionesController.doGet(ReprobacionesController.java:209)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

经过几个小时后，我发现如何获取列的名称，所以我添加了以下行：

        ResultSetMetaData rsmd = rs.getMetaData();
        System.out.println("columnas: "+rsmd.getColumnCount());
        System.out.println(rsmd.getColumnName(1));
        System.out.println(rsmd.getColumnName(2));
        System.out.println(rsmd.getColumnName(3));
        System.out.println(rsmd.getColumnName(4));
        System.out.println(rsmd.getColumnName(5));

跑完后我在控制台上得到了这个：

columnas：5

IdReprobacion

IdCiclo

Materia

Nota

Detalle

所以名为＆＃34; Materia＆＃34;实际上存在，我不知道为什么要把＃34;列找不到异常＆＃34;如果有人能帮助我，我会感激不尽。

JAVA - SQLException抛出存在列未找到

0 个答案: