java - 在这种情况下如何动态为 ResultSet 提供列名称？

Question

我有一个如下所示的ArrayList

  import java.util.ArrayList;

public class Mann {

    public static void main(String args[]) {

        ArrayList<String> billOrderList = new ArrayList<String>();

        list.add("VAT");
        list.add("Discount");
        list.add("SERVICE CHARGE");

        StringBuilder select_query = new StringBuilder();
        select_query.append("Select ");

        for (int i = 0; i < billOrderList.size(); i++) {

            if (i != billOrderList.size() - 1) {
                select_query.append("" + billOrderList.get(i) + " , ");
            } else {
                select_query.append("" + billOrderList.get(i) + "");
            }
        }

        select_query.append(" From VENDOR_ITEMS WHERE vendor_items_id = "
                + vendor_item + "");

        VendorItems_Pstmt = dbConnection.prepareStatement(select_query
                .toString());
        VendorItems_RSet = VendorItems_Pstmt.executeQuery();
        while (VendorItems_RSet.next()) {

            String tax_name = VendorItems_RSet.getString();
        }
    }

}

我如何在 VendorItems_RSet.getString(); 行中给出在这种情况下动态的列名称？

Answer 1

您需要 ResultSetMetaData获取与查询结果关联的列名。
您可以使用 ResultSet.getMetaDate 从 ResultSet 获取 ResultSetMetaData ，您可以迭代它并获取列所有列名称。

ResultSetMetaData  VendorItems_RSet_metaData = VendorItems_RSet.getMetaData(); 
int numberOfColumns = VendorItems_RSet_metaData .getColumnCount(); 
for(int i=1;i<=numberOfColumns;i++)
{   
   String columnName = VendorItems_RSet_metaData.getColumnName(i);
}

我认为您需要所有列数据，以便您可以像这样迭代循环

while (VendorItems_RSet.next()) 
{
  for(int i=1;i<=numberOfColumns;i++)
  {   
     String columnName = VendorItems_RSet_metaData.getColumnName(i);
     String tax_name = VendorItems_RSet.getString(columnName);
     System.out.println(tax_name); 
  }         
}