18262631023123-竞赛第一题SELECT TABLE_SCHEMA AS 数据库, TABLE_NAME AS 表名, COLUMN_NAME AS 字段名, DATA_TYPE AS 数据类型, CHARACTER_MAXIMUM_LENGTH AS 最大长度, IS_NULLABLE AS 是否可为空, COLUMN_DEFAULT AS 默认值, COLUMN_KEY AS 键类型, EXTRA AS 额外信息 FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = ‘xxxx