今天碰到一个问题,查询出一个字段值,形如: 100010,100011,100012,100013,100014,100015,100016,100011,100012,100013,100014,100015,100016
的由逗号分隔的字符串,其中后面(红色部分)的子字符串与前面子字符串重复。去除其中重复的子字符串。web
create or replace function fun_rep_repeat_str(p_str varchar2,p_sep varchar2) return varchar2 deterministic is /* * 字符串中,子字符串去重 * p_str: 须要去重的字符串 * p_sep: 分隔符 * 例: select fun_rep_repeat_str('100010,100011,100012,100013,100014,100015,100016,100011,100012,100013,100014,100015,100016') from dual; */ type v_type is table of varchar2(4000); v_tab v_type; v_res varchar2(4000); cursor c_get_str is select regexp_substr(p_str, '[^' || p_sep || ']+', 1, level) str from dual connect by level <= length(regexp_replace(p_str, '[^' || p_sep || ']')) + 1; begin open c_get_str; fetch c_get_str bulk collect into v_tab; close c_get_str; --集合去重 v_tab := set(v_tab); for x in 1 .. v_tab.count loop v_res := v_res || v_tab(x) || p_sep; end loop; return rtrim(v_res, p_sep); end;
select fun_rep_repeat_str('100010,100011,100012,100013,100014,100015,100016,100011,100012,100013,100014,100015,100016',',') from dual; -- 结果: 100010,100011,100012,100013,100014,100015,100016