code: @SuppressWarnings("resource")
  	public static Table getTableMeta(DataSource ds, String tableName) {
  		final Table table = Table.create(tableName);
  		Connection conn = null;
  		ResultSet rs = null;
  		try {
  			conn = ds.getConnection();
  			final DatabaseMetaData metaData = conn.getMetaData();
  			// 获得主键
  			rs = metaData.getPrimaryKeys(conn.getCatalog(), null, tableName);
  			while (rs.next()) {
  				table.addPk(rs.getString("COLUMN_NAME"));
  			}
  
  			// 获得列
  			rs = metaData.getColumns(conn.getCatalog(), null, tableName, null);
  			while (rs.next()) {
  				table.setColumn(Column.create(tableName, rs));
  			}
  		} catch (SQLException e) {
  			throw new DbRuntimeException("Get columns error!", e);
  		} finally {
  			DbUtil.close(rs, conn);
  		}
  
  		return table;
  	}
docs: 获得表的元信息
  
  @param ds 数据源
  @param tableName 表名
  @return Table对象