格式 REGEXP_LIKE ( expression, pattern [, match_parameter ] )
-- ^X 匹配第一个字符是X
select * from xir_md.tfnd t where regexp_like(t.i_code,'^([A-Z]+|[a-z])');
-- $X 匹配最后一个字符是d
select * from xir_md.tfnd t where regexp_like(t.i_code,'([A-Z]+|[a-z])$');
-- +X 至少匹配一次X
select * from xir_md.tfnd t where regexp_like(t.i_code,'+([a-z]+|[A-Z])');
--- X 匹配0个或多个X
select * from xir_md.tfnd t where regexp_like(t.i_code,'([a-z]+|[A-Z])');
-- .X 匹配首字母后字符含X
select * from xir_md.tfnd t where regexp_like(t.i_code,'.([a-z]+|[A-Z])')