mysql拆分字符串函数

 业务需求：拆分字符串，然后将数字转换成中文描述，返回成以,分割的中文描述 

 

-- 修改结束符，防止在mysql命令行中默认分号直接运行  delimiter $$    -- 创建一个计算拆分后字符串的个数函数  drop function if exists calc_length $$  create function calc_length(str varchar(200), splitstr varchar(5)) returns int(11)  begin   return length(str)-length(replace(str, splitstr, ''))+1;  end $$    -- 创建一个模拟的split拆分字符串的函数  drop function if exists split_string $$  create function split_string(str varchar(200), splitstr varchar(5), strindex int) returns varchar(255)  begin  declare result varchar(255) default '';  set result =reverse(substring_index( reverse(substring_index(str, splitstr, strindex)), splitstr, 1));  return result;  end $$    -- 创建一个循环函数delimiter $$  drop function if exists split_model $$create function split_model(str varchar(200))  returns varchar(2000) begin  declare cnt int default 0;  declare i int default 0;  declare result  VARCHAR(2000) DEFAULT ' ';declare ab  VARCHAR(20)DEFAULT ' ';declare ac  VARCHAR(20)DEFAULT ' ';set cnt = calc_length(str, '|');    while i < cnt   do   set i = i+1;  set ab=split_string(str,'|', i);if ab='1' then set ac='CPM';elseif ab='2'  then set ac= 'CPC';elseif ab='3' then set ac='CPA';elseif ab='4' then set ac='CPT';else set ac='CPS';end if;set result=CONCAT(result,ac,','); END WHILE;return result;end $$  -- 创建一个循环函数delimiter $$  drop function if exists split_mediatype $$create function split_mediatype(str varchar(200))  returns varchar(2000) begin  declare cnt int default 0;  declare i int default 0;  declare result  VARCHAR(2000) DEFAULT ' ';declare ab  VARCHAR(20)DEFAULT ' ';declare ac  VARCHAR(20)DEFAULT ' ';set cnt = calc_length(str, ',');    while i < cnt   do   set i = i+1;  set ab=split_string(str,',', i);if ab='0' then set ac='购物';elseif ab='1'  then set ac= '游戏';elseif ab='2' then set ac='小说';elseif ab='3' then set ac='影视';elseif ab='4' then set ac='教育';elseif ab='5' then set ac='应用';else set ac='工具';end if;set result=CONCAT(result,ac,','); END WHILE;return result;end $$  -- 创建一个循环函数delimiter $$  drop function if exists split_mediauser $$create function split_mediauser(str varchar(200))  returns varchar(2000) begin  declare cnt int default 0;  declare i int default 0;  declare result  VARCHAR(2000) DEFAULT ' ';declare ab  VARCHAR(20)DEFAULT ' ';declare ac  VARCHAR(20)DEFAULT ' ';set cnt = calc_length(str, '|');    while i < cnt   do   set i = i+1;  set ab=split_string(str,'|', i);set ac= (select name_cn FROM sp_user where id=ab);set result=CONCAT(result,ac,','); END WHILE;return result;end $$