在执行statement.execute(sql)时关闭ResultSet

Question

在执行下面的代码时，我得到了错误java.sql.SQLException: ResultSet is java.sql.SQLException

公共类SavePoints {

public void extract(ResultSet rs)
{
     int c;
    try {
        while(rs.next())
        {
        c = rs.getInt("id");
       String d=rs.getString("name");
       String e=rs.getString("city");
       String f=rs.getString("state");
       String g=rs.getString("country");

    //Displaying values
     System.out.println("ID is:"+c+"\tName is:"+d+"\tCity is:"+e+"\tState is:"+f+"\tCountry is:"+g);
        }
    } catch (SQLException e1) {
        e1.printStackTrace();
    }

}

public static void main(String[] args) {
    SavePoints spobj=new SavePoints();
    try {
        Connection con=DriverManager.getConnection("jdbc:odbc:Divya", "SYSTEM", "tiger");
        Statement st=con.createStatement();
        ResultSet rs=st.executeQuery("select * from publishers");
        spobj.extract(rs);
        //DatabaseMetaData databaseMetaData = con.getMetaData();
        //System.out.println(databaseMetaData.getDriverMajorVersion());
        //Savepoint sp=con.setSavepoint("Deleting Rows");
        st.execute("delete from publishers where id=104");
        //con.rollback(sp);
        spobj.extract(rs);
    } catch (SQLException e) {

        e.printStackTrace();
    }


}

}

错误是什么？我找不到它。请让我知道。我是个新手..因此，请用简单的术语解释。我很感谢你的帮助。谢谢:)

Answer 1

您已调用% spobj.extract(rs);两次，

第一次执行此函数时，结果集将移到最后，因为您使用的是rs.next()。

要实现这一点，您必须使用可滚动结果集

Statement st = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, 
                                    ResultSet.CONCUR_READ_ONLY);

对于下一次spobj.extract(rs);的调用，rs.previous()会反转对结果集的调用