TestResultSetMetaDate-结果集元数据

TestResultSetMetaDate-结果集元数据：封装了ResultSet中所有的信息，比如有列数，表中列的别名（lable）,表中列的名字

 

public class TestResultSetMetaDate {
 @Test
 public void testResultSetMetaDate(){
  Connection connection = null;
  Statement s = null;
  ResultSet rs = null;
  try {
   connection = JDBCUtils.getConnection();
   s = connection.createStatement();
   String sql = "select order_id id, order_name name, order_date date from `order` where order_id = 1";
   rs = s.executeQuery(sql);
   ResultSetMetaData rsmd = rs.getMetaData();
   // 1.getColumnCount():获取结果集的列数
   int count = rsmd.getColumnCount();
   
   while(rs.next()){
    for(int i=0; i<count; i++){
     //获取结果集中每列的值
     Object columnValue = rs.getObject(i + 1);
     System.out.println("····"+columnValue);
     //获取表中列的名字
     String columnName = rsmd.getColumnName(i + 1);
     System.out.println("////"+columnName);
     //获取表的列的别名
     String columnLable = rsmd.getColumnLabel(i + 1);
     System.out.println(",,,,,"+columnLable);
    }
   }
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally{  
   JDBCUtils.close(rs, s, connection);
  }
 }