如何获得表主键ID的字段名

方法一：通过connection来获得

	private String getIdName(Connection conn,String tableName){
		String idName = "";
		DatabaseMetaData  metaData = null;
		try {
			 metaData = conn.getMetaData();
			 ResultSet rs = metaData.getColumns(conn.getCatalog(), "%", tableName, "%ID");
			 if(rs.next()){
				 idName = rs.getString("COLUMN_NAME"); 
			 }
		} catch (Exception e) {
			logger.error(e);
		}
		return idName;
	}

方法二：通过结果集ResultSet获得

	private String getIdName(ResultSet rs){
		String idName = "";
		ResultSetMetaData metaData = null;
		try {
			 metaData = rs.getMetaData();
			 idName = metaData.getColumnName(1);
		} catch (Exception e) {
			logger.error("查询表的主键名出错！ ",e);
		}
		return idName;
	} 

其中rs为select * from tableName;的结果集