存储阵列并访问它们

Question

这是我用来从“ GeneID”列中检索数据的编码。 使用此编码，我可以在“ GeneID”列下打印所有名称。 但是我想存储列中的每个名称，以分别访问这些名称。 谁能帮我这个？

String name1[] = new String[100];
int i = 0;
String query = "select distinct GeneID from gene1";
PreparedStatement pest = connection.prepareStatement(query);
ResultSet rs = pest.executeQuery();

while (rs.next()) {
    name1[i] = rs.getString("GeneID");
    System.out.println(name1[i]);
}

rs.close();
pest.close();

Answer 1

对于使用阵列就得增加i的内侧while (rs.next()) {

  String name1[] = new String[100];

    int i = 0;
    String query = "select distinct GeneID from gene1";
    PreparedStatement pest = connection.prepareStatement(query);
    ResultSet rs = pest.executeQuery();

    while (rs.next()) {

        name1[i] = rs.getString("GeneID");
        System.out.println(name1[i]);
      i++;
    }

    rs.close();
    pest.close();
}

为了进行访问，您可以遍历数组

 for(int i;i<name1.length-1;i++){
System.out.println("Id is "+name1[i]);
}

或者你可以使用

for (String id: name1) {           
   System.out.println("Id is "+name1[i]);
}

您还可以使用ArrayList如下存储变量

 ArrayList ar=new ArrayList();

 String query = "select distinct GeneID from gene1";
 PreparedStatement pest = connection.prepareStatement(query);
 ResultSet rs = pest.executeQuery();
 while (rs.next()) {
       String id = rs.getString("GeneID");
        ar.add(id);
    }

    rs.close();
    pest.close();
}

用于遍历ArrayList

for (int i = 0; i < ar.size(); i++) {
            System.out.println("Id is "+ar.get(i));
        }

要么

for (String id : ar) {
            System.out.println("Id is "+ar.get(i));
        }

Answer 2

使用arrayList，以便可以使用.add（）方法，这被证明很有帮助

List ls=new ArrayList();

ResultSet rsp=pss.executeQuery("select * from student");

while(rsp.next()){


ls.add(rsp.getString("your_column_name"));

} 

rsp.close（）;