如何在MySQL存储过程中拆分逗号分隔的文本

Question

如何在MySQL存储过程中拆分逗号分隔文本（ID列表），以便在SQL“IN”语句中使用结果。

SELECT * FROM table WHERE table.id IN (splitStringFunction(commaSeparatedData, ',')); 

Answer 1

你可以做到这一点有两种方式：

1. SQL Library
2. Natively with REGEXP

Answer 2

你可以试试这个MySQL实例。在使用它之前，在其中加入一些类型安全检查（即检查id是整数，或者在插入前匹配正则表达式）。

# BEGIN split statements ids 
DECLARE current_pos INT DEFAULT 1; 
DECLARE delim CHAR DEFAULT ','; 
DECLARE current CHAR DEFAULT ''; 
DECLARE current_id VARCHAR(100) DEFAULT '';; 
CREATE TEMPORARY TABLE ids (`id` VARCHAR(100)); 
split_ids: LOOP 
    SET current = MID(statement_ids, current_pos, 1); 
    IF (current_pos = LENGTH(statement_ids)) THEN 
    IF current != delim THEN SET current_id = CONCAT(current_id,current); END IF; 
    INSERT INTO ids(id) VALUES (current_id); 
    LEAVE split_ids; 
    END IF; 
    IF current = delim THEN 
    INSERT INTO ids(id) VALUES (current_id); 
    SET current_id = ''; 
    ELSE 
    SET current_id = CONCAT(current_id,current); 
    END IF; 
    SET current_pos = current_pos+1; 
END LOOP split_ids; 
# END split statement ids 

# to check ids are correct 
SELECT * FROM ids; 

# to use the ids: 
SELECT * FROM statements WHERE id IN (SELECT id FROM ids); 

Answer 3

OK，略显 “容易”，但不太令人讨厌的人喜欢我的方式：

说你有一个表 'combined_city_state' 它看起来像：

'Chicago, Illinois' 

复制到其他2表格：

CREATE TABLE city LIKE combined_city_state; 
INSERT city SELECT * FROM combined_city_state; 

CREATE TABLE state LIKE combined_city_state; 
INSERT state SELECT * FROM combined_city_state; 

您现在有3个表格，其数据与'combined_city_state'相同。

安装此功能：

CREATE FUNCTION SPLIT_STR(
    x VARCHAR(255), 
    delim VARCHAR(12), 
    pos INT 
) 
RETURNS VARCHAR(255) 
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos), 
     LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1), 
     delim, ''); 

然后将此每个表中删除数据的额外指标：

UPDATE firms 
SET city = (SELECT SPLIT_STR((city), ',', 1)); 


UPDATE firms 
SET state = (SELECT SPLIT_STR((state), ',', 2)); 

这使你只用城市的一列，只是陈述一个。如果您不再需要，现在可以移除原始的'combined_city_state'列。

Answer 4

您可以使用存储过程内的预处理语句来实现此目的。您可以将整个选择查询创建为变量内的字符串，然后将逗号分隔的字符串连接到其IN子句中。然后，您可以从查询字符串变量中创建一个准备好的语句并执行它。

DELIMITER ;; 
create procedure testProc(in listString varchar(255)) 

BEGIN 

set @query = concat('select * from testTable where id in (',listString,');'); 
prepare sql_query from @query; 
execute sql_query; 

END 
;; 

DELIMITER ; 

call testProc("1,2,3"); 

Answer 5

我已经用连字符解析了数据。下面的示例使用固定的文本字符串来演示，只需更改表中相关列名称的引用即可。我玩了很长时间，以确保它能够处理具有不同数量组件的代码，并最终决定添加where子句。你试图分析的大部分数据都会有固定数量的列。

select 
SUBSTRING_INDEX(TS,"-",1) as "1", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",2)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",2)))-1)) as "2", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",3)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",3)))-1)) as "3", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",4)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",4)))-1)) as "4", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",5)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",5)))-1)) as "5", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",6)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",6)))-1)) as "6",reverse(left(reverse(SUBSTRING_INDEX(TS,"-",7)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",7)))-1)) as "7", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",8)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",8)))-1)) as "8", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",9)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",9)))-1)) as "9", 
reverse(left(reverse(SUBSTRING_INDEX(TS,"-",10)),locate("-",reverse(SUBSTRING_INDEX(TS,"-",10)))-1)) as "10" 
from (select "aaa-bbb-ccc-ddd-eee-fff-ggg-hhh-iii-jjj" as TS) as S 
where (LENGTH(TS)-LENGTH(REPLACE(TS,'-',''))) =9 

Answer 6

我很惊讶这一个班轮不能正常这里提到：

SELECT * FROM table 
WHERE id in (SELECT convert(int,Value) FROM dbo.Split(@list_string,',') 

所有你需要的是一个Split SQL function像一个低于该会在其他方面得心应手，以及：

CREATE FUNCTION dbo.Split 
(
    @List nvarchar(2000), 
    @SplitOn nvarchar(5) 
) 
RETURNS @RtnValue table 
(

    Id int identity(1,1), 
    Value nvarchar(100) 
) 
AS 
BEGIN 
While (Charindex(@SplitOn,@List)>0) 
Begin 
    Insert Into @RtnValue (value) 
    Select 
     Value = ltrim(rtrim(Substring(@List,1,Charindex(@SplitOn,@List)-1))) 
     Set @List = Substring(@List,Charindex(@SplitOn,@List)+len(@SplitOn),len(@List)) 
End 

Insert Into @RtnValue (Value) 
Select Value = ltrim(rtrim(@List)) 

Return 
END 

Answer 7

这是简单得要命的MySQL：

SELECT * FROM table WHERE FIND_IN_SET(table.id, commaSeparatedData); 

参考：http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_find-in-set