如何在MySQL存儲過程中拆分逗號分隔的文本

Question

如何在MySQL存儲過程中拆分逗號分隔文本（ID列表），以便在SQL「IN」語句中使用結果。

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

Answer 1

你可以做到這一點有兩種方式：

1. SQL Library
2. Natively with REGEXP

Answer 2

你可以試試這個MySQL實例。在使用它之前，在其中加入一些類型安全檢查（即檢查id是整數，或者在插入前匹配正則表達式）。

# 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，略顯 「容易」，但不太令人討厭的人喜歡我的方式：

說你有一個表 'combined_city_state' 它看起來像：

'Chicago, Illinois' 

複製到其他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; 

您現在有3個表格，其數據與'combined_city_state'相同。

安裝此功能：

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, ''); 

然後將此每個表中刪除數據的額外指標：

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


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

這使你只用城市的一列，只是陳述一個。如果您不再需要，現在可以移除原始的'combined_city_state'列。

Answer 4

您可以使用存儲過程內的預處理語句來實現此目的。您可以將整個選擇查詢創建爲變量內的字符串，然後將逗號分隔的字符串連接到其IN子句中。然後，您可以從查詢字符串變量中創建一個準備好的語句並執行它。

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

我已經用連字符解析了數據。下面的示例使用固定的文本字符串來演示，只需更改表中相關列名稱的引用即可。我玩了很長時間，以確保它能夠處理具有不同數量組件的代碼，並最終決定添加where子句。你試圖分析的大部分數據都會有固定數量的列。

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

我很驚訝這一個班輪不能正常這裏提到：

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

所有你需要的是一個Split SQL function像一個低於該會在其他方面得心應手，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

這是簡單得要命的MySQL：

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

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