Flink SQL保留关键字官方参考资料：SQL | Apache Flink在使用flink时，如果不小心用到了flink保留关键字，会产生关键字错误。关于flink关键字，官方原话是“Although not every SQL feature is implemented yet, some string combinations are already reserved as keywords for future use. If you want to use one of the following strings as