can anybody tell me how to implement a split function in mysql which behaves like Javascript split.
I want a function like this
SELECT Split('a,b,c,d', ',') AS splitted
Which give result like
splitted
--------------
a
b
c
d
Can anybody help me?
I saw some answers here, and somewhere else, but those functions need the position of string to be returned, which I don't want/have
Thank you
It is possible:
-- Preparation
CREATE TABLE tb_Digits (d int(11) UNSIGNED NOT NULL PRIMARY KEY);
INSERT tb_Digits VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
INSERT IGNORE tb_Digits
SELECT o1.d+o2.d*10+o3.d*100+o4.d*1000 d FROM tb_Digits o4, tb_Digits o3, tb_Digits o2, tb_Digits o1;
CREATE PROCEDURE pc_splitStr(IN in_string TEXT, IN in_separator CHAR(1))
COMMENT 'Use (SELECT word FROM return_splitStr) para ver o resultado'
BEGIN
DECLARE o_limit INT(11) UNSIGNED DEFAULT LENGTH(in_string)-LENGTH(REPLACE(in_string,in_separator,''))+1;
DROP TABLE IF EXISTS return_splitStr;
CREATE TEMPORARY TABLE return_splitStr (word TEXT);
INSERT return_splitStr
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(in_string, in_separator, d.d), in_separator, -1)
FROM tb_Digits d
WHERE d.d>0 AND d.d<=o_limit;
END;
-- Execution
CALL pc_splitStr('a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z',',');
SELECT word FROM return_splitStr;
You can create a function and return the specific result you are waiting for.
here is an example with multi ids in one column extracted and queried to get the specific values :
DROP FUNCTION IF EXISTS getValuesByOptionIds;
DELIMITER $$
CREATE FUNCTION getValuesByOptionIds
(
optionIds VARCHAR(255)
)
RETURNS VARCHAR(255)
DETERMINISTIC
BEGIN
DECLARE iter INTEGER DEFAULT 0;
DECLARE result VARCHAR(255) DEFAULT '';
DECLARE previousIter VARCHAR(255) DEFAULT '';
iters: WHILE LENGTH(SUBSTRING_INDEX(optionIds, ',', iter + 1)) != LENGTH(previousIter) DO
SET iter = iter + 1;
SET previousIter = SUBSTRING_INDEX(optionIds, ',', iter);
IF iter = 1 THEN
SET result = (select tmp.value from eav_attribute_option_value tmp where tmp.option_id = SUBSTRING_INDEX(optionIds, ',', iter));
ELSEIF iter > 1 THEN
SET result = concat(result, ',', (select tmp.value from eav_attribute_option_value tmp where tmp.option_id = SUBSTRING_INDEX(SUBSTRING_INDEX(optionIds, ',', iter), ',', -1)));
END IF;
END WHILE iters;
RETURN result;
END$$
DELIMITER ;
Related
can anybody tell me how to implement a split function in mysql which behaves like Javascript split.
I want a function like this
SELECT Split('a,b,c,d', ',') AS splitted
Which give result like
splitted
--------------
a
b
c
d
Can anybody help me?
I saw some answers here, and somewhere else, but those functions need the position of string to be returned, which I don't want/have
Thank you
It is possible:
-- Preparation
CREATE TABLE tb_Digits (d int(11) UNSIGNED NOT NULL PRIMARY KEY);
INSERT tb_Digits VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
INSERT IGNORE tb_Digits
SELECT o1.d+o2.d*10+o3.d*100+o4.d*1000 d FROM tb_Digits o4, tb_Digits o3, tb_Digits o2, tb_Digits o1;
CREATE PROCEDURE pc_splitStr(IN in_string TEXT, IN in_separator CHAR(1))
COMMENT 'Use (SELECT word FROM return_splitStr) para ver o resultado'
BEGIN
DECLARE o_limit INT(11) UNSIGNED DEFAULT LENGTH(in_string)-LENGTH(REPLACE(in_string,in_separator,''))+1;
DROP TABLE IF EXISTS return_splitStr;
CREATE TEMPORARY TABLE return_splitStr (word TEXT);
INSERT return_splitStr
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(in_string, in_separator, d.d), in_separator, -1)
FROM tb_Digits d
WHERE d.d>0 AND d.d<=o_limit;
END;
-- Execution
CALL pc_splitStr('a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z',',');
SELECT word FROM return_splitStr;
You can create a function and return the specific result you are waiting for.
here is an example with multi ids in one column extracted and queried to get the specific values :
DROP FUNCTION IF EXISTS getValuesByOptionIds;
DELIMITER $$
CREATE FUNCTION getValuesByOptionIds
(
optionIds VARCHAR(255)
)
RETURNS VARCHAR(255)
DETERMINISTIC
BEGIN
DECLARE iter INTEGER DEFAULT 0;
DECLARE result VARCHAR(255) DEFAULT '';
DECLARE previousIter VARCHAR(255) DEFAULT '';
iters: WHILE LENGTH(SUBSTRING_INDEX(optionIds, ',', iter + 1)) != LENGTH(previousIter) DO
SET iter = iter + 1;
SET previousIter = SUBSTRING_INDEX(optionIds, ',', iter);
IF iter = 1 THEN
SET result = (select tmp.value from eav_attribute_option_value tmp where tmp.option_id = SUBSTRING_INDEX(optionIds, ',', iter));
ELSEIF iter > 1 THEN
SET result = concat(result, ',', (select tmp.value from eav_attribute_option_value tmp where tmp.option_id = SUBSTRING_INDEX(SUBSTRING_INDEX(optionIds, ',', iter), ',', -1)));
END IF;
END WHILE iters;
RETURN result;
END$$
DELIMITER ;
There is a MySQL function in our web system to generate Code. The structure of the code is
district_cd(length:2) + date(length:8) + sequence no(length:5,start at 1).<like : ab2016090800001>
The sequence no was saved in table and will be updated (+1) when generate a new code.
But sometimes it returned two same codes and makes us fall in trouble. Here are the captures to replicate this problem, I will attach the DDL after this.
Step 1.Client1->change to manual commit then generate a code, but do not commit.
SET autocommit = 0;
select * from applies;
select * from sequence where apply_date = "2016-09-08";
select nextval("ab");
insert into applies (apply_id,apply_no,created,district_cd) values (2,"ab2016090800002","ab",now());
select * from sequence where apply_date = "2016-09-08";
Step2.Client2->change to manual commit then generate a code, stuck as Client1 locked
SET autocommit = 0;
select * from applies;
select * from sequence where apply_date = "2016-09-08";
insert into applies (apply_id,apply_no,created,district_cd) values (3,"ab20160908123456780","ab",now());
Step3.Client1->commit;
commit;
select * from sequence where apply_date = "2016-09-08";
Step4.Client2->code was generated and two records appeared in sequence table
select * from sequence where apply_date = "2016-09-08";
capture of Step4
Step5.Client2->commit;one of the two records that appeared in sequence table was deleted.The codes generated are duplicated.
commit;
select * from sequence where apply_date = "2016-09-08";
select * from applies;
capture of Step5
※DDL
Table:applies (apply_no:save the code)
CREATE TABLE `applies` (
`apply_id` varchar(100) NOT NULL DEFAULT '',
`apply_no` varchar(100) NOT NULL DEFAULT '',
`district_cd` varchar(100) DEFAULT NULL,
`created` datetime DEFAULT NULL,
PRIMARY KEY (`apply_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Table:sequence (current_value:save current sequnce value)
CREATE TABLE `sequence` (
`district_cd` varchar(3) NOT NULL DEFAULT '',
`current_value` int(11) NOT NULL DEFAULT '0',
`apply_date` date NOT NULL DEFAULT '0000-00-00',
PRIMARY KEY (`district_cd`,`current_value`,`apply_date`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Function:currval->get current sequence value by district_cd
DELIMITER ;;
CREATE DEFINER=`usr`#`%` FUNCTION `currval`(d VARCHAR(3)) RETURNS int(11)
DETERMINISTIC
BEGIN
DECLARE value INTEGER;
DECLARE needInitSequence INTEGER;
DECLARE today DATE;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET needInitSequence = 1;
SET value = 0;
SET today = current_date();
SELECT `current_value` INTO value
FROM `sequence`
WHERE `district_cd` = d AND `apply_date` = today limit 1;
IF needInitSequence = 1 THEN
INSERT INTO `sequence` (`district_cd`, `current_value`, `apply_date`) VALUES (d, value, today);
END IF;
RETURN value;
END
;;
DELIMITER ;
Function:nextval->generate code by district_cd
DELIMITER ;;
CREATE DEFINER=`usr`#`%` FUNCTION `nextval`(d VARCHAR(3)) RETURNS varchar(16) CHARSET utf8
DETERMINISTIC
BEGIN
DECLARE value INTEGER;
SET value = currval(d);
UPDATE `sequence`
SET `current_value` = `current_value` + 1
WHERE `district_cd` = d AND `apply_date` = current_date();
RETURN concat(d, date_format(now(), '%Y%m%d'), LPAD(currval(d), 5, '0'));
END
;;
DELIMITER ;
Triggers of applies->a business logic,if the length of apply_no is greater than 18,it will call the function:nextval to generate a new code
DELIMITER ;;
CREATE TRIGGER `convert_long_no` BEFORE INSERT ON `applies` FOR EACH ROW BEGIN
IF ((SELECT LENGTH(NEW.apply_no)) >= 18) THEN
SET NEW.apply_no = (SELECT nextval(NEW.district_cd));
END IF;
END
;;
DELIMITER ;
My Questions:
Why did the function:nextval returns two same codes?
Why did two records appear in sequnce when update the record.
I have developed a function for split string in tsql but mysql don't have some built in functions. I needed to function in MYSQL as i am new in mysql. Function should accept 2 parameters
1. String to be split
2. separator (',' or whatever)
Kindly reply me.
i had found solution on the internet you can into that.
DELIMITER //
DROP FUNCTION IF EXISTS `splitAndTranslate` //
CREATE FUNCTION splitAndTranslate(str TEXT, delim VARCHAR(124))
RETURNS TEXT
DETERMINISTIC
BEGIN
DECLARE i INT DEFAULT 0; -- total number of delimiters
DECLARE ctr INT DEFAULT 0; -- counter for the loop
DECLARE str_len INT; -- string length,self explanatory
DECLARE out_str text DEFAULT ''; -- return string holder
DECLARE temp_str text DEFAULT ''; -- temporary string holder
DECLARE temp_val VARCHAR(255) DEFAULT ''; -- temporary string holder for query
-- get length
SET str_len=LENGTH(str);
SET i = (LENGTH(str)-LENGTH(REPLACE(str, delim, '')))/LENGTH(delim) + 1;
-- get total number delimeters and add 1
-- add 1 since total separated values are 1 more than the number of delimiters
-- start of while loop
WHILE(ctr<i) DO
-- add 1 to the counter, which will also be used to get the value of the string
SET ctr=ctr+1;
-- get value separated by delimiter using ctr as the index
SET temp_str = REPLACE(SUBSTRING(SUBSTRING_INDEX(str, delim, ctr), LENGTH(SUBSTRING_INDEX(str, delim,ctr - 1)) + 1), delim, '');
-- query real value and insert into temporary value holder, temp_str contains the exploded ID
SELECT <real_value_column> INTO temp_val FROM <my_table> WHERE <table_id>=temp_str;
-- concat real value into output string separated by delimiter
SET out_str=CONCAT(out_str, temp_val, ',');
END WHILE;
-- end of while loop
-- trim delimiter from end of string
SET out_str=TRIM(TRAILING delim FROM out_str);
RETURN(out_str); -- return
END//
reference http://www.slickdev.com/2008/09/15/mysql-query-real-values-from-delimiter-separated-string-ids/
In mysql they they dont support some functionality like sqlserver. so spliting will be difficult in mysql
SELECT e.`studentId`, SPLIT(",", c.`courseNames`)[e.`courseId`]
FROM ..
SELECT TRIM(SUBSTRING_INDEX(yourcolumn,',',1)), TRIM(SUBSTRING_INDEX(yourcolumn,',',-1)) FROM yourtable
CREATE FUNCTION [dbo].[SplitString]
(
#RowData nvarchar(2000),
#SplitOn nvarchar(5)
)
RETURNS #RtnValue table
(
--Id int identity(1,1),
Data nvarchar(100)
)
AS
BEGIN
Declare #Cnt int
Set #Cnt = 1
While (Charindex(#SplitOn,#RowData)>0)
Begin
Insert Into #RtnValue (data)
Select
Data = ltrim(rtrim(Substring(#RowData,1,Charindex(#SplitOn,#RowData)-1)))
Set #RowData = Substring(#RowData,Charindex(#SplitOn,#RowData)+1,len(#RowData))
Set #Cnt = #Cnt + 1
End
Insert Into #RtnValue (data)
Select Data = ltrim(rtrim(#RowData))
Return
END
I have a table named assignRole.
I am passing string of userid (int) csv ,and passing roleid(int).
I want a stored procedure which split userid from string and take roleid and insert these values in table.this thing is to happen for all values in userid string.
First, create a function:
CREATE FUNCTION [dbo].[SplitInts]
(
#List VARCHAR(MAX),
#Delimiter CHAR(1)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN ( SELECT Item = CONVERT(INT, Item) FROM (
SELECT Item = x.i.value('(./text())[1]', 'int') FROM (
SELECT [XML] = CONVERT(XML, '<i>' + REPLACE(#List, #Delimiter, '</i><i>')
+ '</i>').query('.') ) AS a CROSS APPLY [XML].nodes('i') AS x(i)) AS y
WHERE Item IS NOT NULL
);
Now you can say:
INSERT dbo.assignRole(RoleID, UserID)
SELECT #RoleID, Item
FROM dbo.SplitInts(#UserIDList, ',');
I like to use a table-valued function to do the split.
IF OBJECT_ID (N'dbo.StrSplit') IS NOT NULL DROP FUNCTION dbo.[StrSplit]
GO
CREATE FUNCTION [dbo].[StrSplit]
(
#String VARCHAR(MAX), #Delimiter char(1)
)
RETURNS
#Results TABLE (
Items NVARCHAR(MAX)
)
AS
BEGIN
DECLARE #INDEX INT
DECLARE #SLICE nvarchar(MAX)
-- HAVE TO SET TO 1 SO IT DOESNT EQUAL ZERO FIRST TIME IN LOOP
SELECT #INDEX = 1
-- Early exit if passed string is null
IF #String IS NULL RETURN
WHILE #INDEX !=0
BEGIN
-- GET THE INDEX OF THE FIRST OCCURENCE OF THE SPLIT CHARACTER
SELECT #INDEX = CHARINDEX(#Delimiter,#STRING)
-- NOW PUSH EVERYTHING TO THE LEFT OF IT INTO THE SLICE VARIABLE
IF #INDEX !=0
SELECT #SLICE = LEFT(#STRING,#INDEX - 1)
ELSE
SELECT #SLICE = #STRING
-- PUT THE ITEM INTO THE RESULTS SET
INSERT INTO #Results(Items) VALUES(#SLICE)
-- CHOP THE ITEM REMOVED OFF THE MAIN STRING
SELECT #STRING = RIGHT(#STRING,LEN(#STRING) - #INDEX)
-- BREAK OUT IF WE ARE DONE
IF LEN(#STRING) = 0 BREAK
END
RETURN
END
GO
GRANT SELECT ON [dbo].[StrSplit] TO [public]
I have a table which contains header information for transactions. The transactions belong to different projects.
In the header I have columns:
rhguid - uniqueidentifier
rhserial - int
rh_projectID - int
First I insert the row (there's more columns)
Then I calculate the serial number for that project:
update responseheader
set rhSerial = 1 + (select isnull(max(rhSerial), 0)
from responseheader
where (rhstatus = 0) AND (rh_projectID = 1234))
where
(rhGUID = <preassignedGUID>);
However when there are many transactions happening at the same time for a project I am finding duplicate rhserial values.
I'm doing this in classic ASP with SQL Server 2008.
Is there a better way?
From your example, it doesn't look like you're using a transaction. My guess is that the SELECT portion of the statement is running as READ UNCOMMITTED, otherwise you would not see duplicates. There are ways to start transactions with ADO, but I prefer using stored procedures instead.
Try implementing something like this:
CREATE PROC dbo.ResponseHeader_Insert
<more data to insert>,
#ProjectID INT,
#Status SMALLINT
as
insert responseheader (column names here)
select <param values here>, isnull(max(rhSerial), 0) + 1
from responseheader
where (rhstatus = #Status) AND (rh_projectID = #ProjectID))
If this doesn't work for ya, try creating sequence tables (one for each sequence).
create table <tablename> (
SeqID int identity(1,1) primary key,
SeqVal varchar(1)
)
Create a procedure to get the next identity:
create procedure GetNewSeqVal_<tablename>
as
begin
declare #NewSeqValue int
set NOCOUNT ON
insert into <tablename> (SeqVal) values ('a')
set #NewSeqValue = scope_identity()
delete from <tablename> WITH (READPAST)
return #NewSeqValue
end
If there are too many sequence tables that need to be created or you want to create sequences on the fly, try this approach:
Create table AllSequences (
SeqName nvarchar(255) primary key, -- name of the sequence
Seed int not null default(1), -- seed value
Incr int not null default(1), -- incremental
Currval int
)
Go
create procedure usp_CreateNewSeq
#SeqName nvarchar(255),
#seed int = 0,
#incr int = 1
as
begin
declare #currval int
if exists (
select 1 from AllSequences
where SeqName = #SeqName )
begin
print 'Sequence already exists.'
return 1
end
if #seed is null set #seed = 1
if #incr is null set #incr = 1
set #currval = #seed
insert into AllSequences (SeqName, Seed, Incr, CurrVal)
values (#SeqName, #Seed, #Incr, #CurrVal)
end
go
create procedure usp_GetNewSeqVal
#SeqName nvarchar(255)
as
begin
declare #NewSeqVal int
set NOCOUNT ON
update AllSequences
set #NewSeqVal = CurrVal = CurrVal+Incr
where SeqName = #SeqName
if ##rowcount = 0 begin
print 'Sequence does not exist'
return
end
return #NewSeqVal
end
go