mysql-求教！下面的MySQL代码怎么改成sqlserver的？拜托拜托！

CREATE TABLE trade (
tradeid int NOT NULL PRIMARY KEY identity(17,1),
userid int NOT NULL,
tradetime datetime NOT NULL,
KEY "user_id_fk" ("userid"),
CONSTRAINT "user_id_fk" FOREIGN KEY ("userid") REFERENCES "userinfo" ("userid")
)

不知道怎么传图片，前面的我改过来了，还有后面两句的报错，倒数第二句“key”"userid"，倒数第一句是"userid" "userid"

谢谢了，对数据库不太懂