Oracle反转倒置函数

CREATE OR REPLACE FUNCTION REVERSE_F(p_str VARCHAR2, p_delimiter VARCHAR2:='') RETURN VARCHAR2 IS v_return VARCHAR2(4000); vp_str VARCHAR2(4000) := p_str; v_idx number; vp_len number := length(p_delimiter); BEGIN if (p_delimiter is null) then select reverse(p_str) into v_return from dual; else loop v_idx := instr(vp_str, p_delimiter); if (v_idx = 0) then v_return := vp_str || v_return; exit; elsif (v_idx = 1) then v_return := substr(vp_str, 1, vp_len) || v_return; vp_str := substr(vp_str, vp_len + 1); else v_return := substr(vp_str, 1, v_idx - 1) || v_return; vp_str := substr(vp_str, v_idx); end if; end loop; end if; RETURN v_return; END REVERSE_F;