Oracle 自定义函数中的sql语句的 单引号嵌套单引号的处理 + 仿 Mysql 中的 group_cat（）

CREATE OR REPLACE FUNCTION F_CONCAT_ROW_COMMUNITY_LABEL(p_field IN VARCHAR2,

p_parent_id IN VARCHAR2,

p_splicing IN VARCHAR2)

RETURN VARCHAR2 IS

retResult VARCHAR2(32767);

TYPE cur_type IS REF CURSOR;

rscur cur_type;

rsVal VARCHAR2(2000);

cnt INTEGER;

BEGIN

cnt := 0;

OPEN rscur FOR 'select distinct cl.' || p_field || ' from community_label cl join bkm_relation br on(br.child_id = cl.id)

where br.relation_type = ''2'' and br.parent_id in (

select v.id from v_community_knowledge v

where v.deleted_flag = ''0'' and v.root_id = (

select v2.root_id from v_community_knowledge v2

where v2.id =''' || p_parent_id || ''' ))';

LOOP

FETCH rscur

INTO rsVal;

EXIT WHEN rscur%NOTFOUND;

IF cnt > 0 THEN

retResult := retResult || p_splicing;

END IF;

retResult := retResult || rsVal;

cnt := cnt + 1;

END LOOP;

CLOSE rscur;

return retResult;

EXCEPTION

-- exception handlers begin

WHEN VALUE_ERROR THEN

--

retResult := '';

RETURN retResult;

END F_CONCAT_ROW_COMMUNITY_LABEL;

/**

* example: select F_CONCAT_ROW('id','community_kn_catagory','3',id,',') from community_knowledge;

* 2013/3/11

**/