public Map<String, Object> getKeys() {
		if (this.keyList.size() == 0) {
			return null;
		}
		if (this.keyList.size() > 1) {
			throw new RetrievalIdException("getKeys方法只适用于单个主键的表结构，但当前表结构包含多个主键:" + this.keyList);
		}
		return this.keyList.get(0);
	}