【问题】
I have a MySQL column that is defined as text. The column, if not null, always contains a list floats separated by a newline character.

I have been tasked with making the total amount of those floats searchable with min and max constraints.

In the where clause, I would like to be able split the column by a newline character and sum all of the resulting strings as floats.

Is this possible?

有人给出答案：

DELIMITER $$

CREATE function split_n_sum(str text) returns DECIMAL(36,4)

begin

declare location int;

declare result decimal(36,4);

declare tmp_str varchar(1024);

declare _delimiter varchar(128);

set _delimiter=‘\r\n’;

set result=0;

set tmp_str=ltrim(rtrim(str));

set location=INSTR(tmp_str,_delimiter);

if location=0 and length(tmp_str)>0 then

set result=cast(tmp_str as decimal(36,4));

set tmp_str='';

end if;

while location<>0 do

set result = result+cast(substring(tmp_str,1,location-length(_delimiter)) as decimal(36,4));

set tmp_str=substring(tmp_str,location+length(_delimiter), length(tmp_str));

set location=INSTR(tmp_str,_delimiter);

end while;

if length(tmp_str)>0 then

set result=result+cast(tmp_str as decimal(36,4));

end if;

return result;

end$$

【回答】

用 SQL 做拆串处理很麻烦，用 SPL 只要两行：

脚本写好后，在其他应用程序中，就可以利用集算器 JDBC 调用该数据集了。Java 如何调用 SPL 脚本