显式类型转换是用cast将一种数据类型的值转换为另一种类型的值的行为，在MaxCompute SQL中支持的显式 类型转换如下： % & && ( ) * + - . / ; < <= <> = > >= ? ADD ALL ALTER AND AS ASC BETWEEN BIGINT BOOLEAN BY CASE CAST COLUMN COMMENT CREATE DESC DISTINCT DISTRIBUTE DOUBLE DROP ELSE FALSE FROM FULL GROUP IF IN INSERT INTO IS JOIN LEFT LIFECYCLE LIKE LIMIT MAPJOIN NOT NULL ON OR ORDER OUTER OVERWRITE PARTITION RENAME REPLACE RIGHT RLIKE SELECT SORT STRING TABLE THEN TOUCH TRUE UNION VIEW WHEN WHERE From/To Bigint Double S
