docs: public int update(Connection conn, Entity record, Entity where) throws SQLException {
  		checkConn(conn);
  		if(CollectionUtil.isEmpty(record)){
  			throw new SQLException("Empty entity provided!");
  		}
  		if(CollectionUtil.isEmpty(where)){
  			//不允许做全表更新
  			throw new SQLException("Empty where provided!");
  		}
  		
  		//表名可以从被更新记录的Entity中获得，也可以从Where中获得
  		String tableName = record.getTableName();
  		if(StrUtil.isBlank(tableName)){
  			tableName = where.getTableName();
  			record.setTableName(tableName);
  		}
  		
  		final Query query = new Query(SqlUtil.buildConditions(where), tableName);
  		PreparedStatement ps = null;
  		try {
  			ps = dialect.psForUpdate(conn, record, query);
  			return ps.executeUpdate();
  		} catch (SQLException e) {
  			throw e;
  		} finally {
  			DbUtil.close(ps);
  		}
  	}