RDS创建function报错 本地运行正常 求解

我本地正常运行的 function，可是我在 rds数据库 中创建报错

CREATE TABLE t_sys_sequence (
  number_type varchar(255) NOT NULL DEFAULT '' COMMENT '编号类型',
  sequence_no bigint(20) DEFAULT NULL COMMENT '序列号',
  PRIMARY KEY (number_type)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE  FUNCTION getSysNumber(codeType VARCHAR(255),startValue INTEGER(11)) RETURNS bigint(20)
BEGIN
    if startValue is  null then
    set startValue = 1;
  end if;
    set @sn = startValue;
    INSERT INTO t_sys_sequence (number_type,sequence_no)
    VALUES (codeType,startValue) ON DUPLICATE KEY UPDATE sequence_no=@sn:=sequence_no+1;
    RETURN(@sn);
END;




【拆分SQL完成】：将执行SQL语句数量：（3条），拆分SQL耗时：（0ms.）【执行SQL：(1)】CREATE FUNCTION `getSysNumber`(codeType VARCHAR(255),startValue INTEGER(11)) RETURNS bigint(20)BEGINif startValue is null thenset startValue = 1执行失败，失败原因：You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 4