Add columns dynamically and Later Parse values in the respective columns - sql-server

Question

I have an SP which accepts the Inputtable as parameter, My Inputtable is as shown in the code
`create table inputTable ( id int,ItemQty varchar(100))
insert into inputTable(id, ItemQty) values(1,'a,b,c')
insert into inputTable(id, ItemQty) values(2,'x,y')
insert into inputTable(id, ItemQty) values(3,'l,m,n,o,p')
insert into inputTable(id, ItemQty) values(4,'a,b')
insert into inputTable(id, ItemQty) values(5,'m')`
and SP i have written is like below
`ALTER PROCEDURE [dbo].[Column_Dynamics] (#tablename varchar(50))
AS
BEGIN
-----
declare #maxcount as int
set #maxcount='select MAX(len(ITEMQTY) - len(replace(ITEMQTY, '','', '''')) +1) from '+#tablename
exec('select MAX(len(ITEMQTY) - len(replace(ITEMQTY, '','', '''')) +1) from '+#tablename)
print #maxcount
exec #maxcount
print #maxcount
declare #var varchar(100)
IF EXISTS(SELECT * FROM sys.columns WHERE object_id = Object_id(#tablename))
set #var='alter table '+ #tablename +' ADD column QTY1'
exec(#var)
select * from #tablename
select max(len(ItemQty))-max(len(replace(ItemQty, ',', ''))-1) from inputtable
END`
My table is :
step 1 ) I want to add the columns dynamically to inputtable like QTY1,QTY2,QTY3,QTY4,QTY5 because maximum count of ItemQty column is 5, by considering comma as delimiter as shown in figure1
**step 2) ** Parse values in the respective columns(by considering the delimiter comma (,).as shown in figure2
Later SP: I got till here, But Not getting the second step, that is update Parse values in the respective columns.
ALTER PROCEDURE dynamic_tbl (#tablename varchar(50))
AS
BEGIN
DECLARE #ColumnCount int
DECLARE #rowcount TABLE (Value int);
INSERT INTO #rowcount
EXEC('select MAX(len(ITEMQTY) - len(replace(ITEMQTY, '','', '''')) +1) from '+#tablename);
SELECT #ColumnCount = Value FROM #rowcount;
Declare #ColumnName nvarchar(10)='qty_'
Declare #count int =0
IF(#ColumnCount>0)
BEGIN
IF (EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'dbo' AND TABLE_NAME = 'dyn_tbl'))
BEGIN
DROP TABLE dyn_tbl
END
select * into dyn_tbl from inputtable
SET #count=#count +1;
WHile(#ColumnCount>=#count)
BEGIN
SET #ColumnName='qty_'+CONVERT(varchar(2),#count)
EXEC ('ALTER TABLE dyn_tbl ADD ['+#ColumnName +'] varchar(20)')
declare #myvar as varchar(max)
set #myvar='update '+#tablename+' set '+#ColumnName +' =itemQty'
--exec dynamic_tbl 'dyn_tbl'
--select * from dyn_tbl
--CAST('<A>'+REPLACE(ITEMQTY, ',', '</A><A>')+'</A>' AS XML)
print #myvar
exec(#myvar)
SET #count=#count +1;
END
END
----
END

Answer 1

Procedure to alter given table dynamically based on column length as you have asked
Alter PROCEDURE [dbo].[Column_Dynamics] (#tablename varchar(50))
AS
BEGIN
drop table ##temp
declare #query1 varchar(max)
exec ( '
create table ##temp (id int identity,columnsl varchar(100))
declare #maxcount as int
set #maxcount = (select MAX(len(ITEMQTY) - len(replace(ITEMQTY, '','', '''')) +1) from '+#tablename+')
declare #count int = 1
while (#count <= #maxcount)
begin
declare #colvar nvarchar(100)= ''QTY''
set #colvar = concat(#colvar,#count)
set #count = #count + 1
insert into ##temp select #colvar
end
')
declare #tempstart int = 1
declare #templast int = (select count(*) from ##temp)
declare #updatecol varchar(100) = ''
while (#tempstart <= #templast)
Begin
set #updatecol = (select columnsl from ##temp where id = #tempstart)
exec ('alter table '+#tablename+' Add '+#updatecol+' varchar(100) ')
set #tempstart = #tempstart + 1
end
End
output for inputTable:
id ItemQty QTY1 QTY2 QTY3 QTY4 QTY5
1 a,b,c NULL NULL NULL NULL NULL
2 x,y NULL NULL NULL NULL NULL
3 l,m,n,o,p NULL NULL NULL NULL NULL
4 a,b NULL NULL NULL NULL NULL
5 m NULL NULL NULL NULL NULL
may not be the best way but works.
edit
Altered above procedure to perform both actions, Please use below procedure
Alter PROCEDURE [dbo].[Column_Dynamics] (#tablename varchar(50))
AS
BEGIN
-- declare #tablename varchar(100) = 'inputTable'
drop table #temp if object_id('temp..#temp') is not null drop table #temp
declare #query1 varchar(max)
create table #temp (id int identity,columnsl varchar(100))
exec ( '
declare #maxcount as int
set #maxcount = (select MAX(len(ITEMQTY) - len(replace(ITEMQTY, '','', '''')) +1) from '+#tablename+')
declare #count int = 1
while (#count <= #maxcount)
begin
declare #colvar nvarchar(100)= ''QTY''
set #colvar = concat(#colvar,#count)
set #count = #count + 1
insert into #temp
select #colvar
end
')
declare #tempstart int = 1
declare #templast int = (select count(*) from #temp)
declare #updatecol varchar(100) = ''
declare #itemqty varchar(100)
while (#tempstart <= #templast)
Begin
set #updatecol = (select columnsl from #temp where id = #tempstart)
exec ('alter table '+#tablename+' Add '+#updatecol+' varchar(100) ')
set #tempstart = #tempstart + 1
end
declare #sysvar table (id int identity,cols varchar(100))
insert into #sysvar select sys.columns.name AS ColumnName FROM sys.columns JOIN sys.tables ON sys.columns.object_id = sys.tables.object_id WHERE sys.tables.name = 'inputTable'
declare #finvar table (id int identity,cols varchar(100))
insert into #finvar select cols from #sysvar where id not in (1,2)
declare #cat int = 1 declare #dog int = (select max(id) from inputTable)
while (#cat <= #dog)
begin
drop table #tab2
if object_id('temp..#tab2') is not null drop table #tab2
create table #tab2 (id int identity,fnvalues varchar(100))
set #itemqty = (select itemqty from inputTable where id = #cat)
insert into #tab2 select item from [dbo].[fnSplit](#itemQty,',')
declare #cn int = 1
declare #max int = (select max(id) from #tab2)
declare #sql nvarchar (1000);
while (#cn <= #max)
begin
declare #upcol varchar(100) = (select fnvalues from #tab2 where id = #cn)
declare #plscol varchar(100) = (select cols from #finvar where id = #cn)
set #sql = N'update '+#tablename+' set ' + #plscol + '= '''+#upcol+''' where id = '''+cast(#cat as varchar(10))+''' ';
select #sql
exec sp_executesql #sql;
set #cn = #cn + 1
end
set #cat = #cat + 1
End
End
output:
id ItemQty QTY1 QTY2 QTY3 QTY4 QTY5
1 a,b,c a b c NULL NULL
2 x,y x y NULL NULL NULL
3 l,m,n,o,p l m n o p
4 a,b a b NULL NULL NULL
5 m m NULL NULL NULL NULL
did not optimize the query but works fine.

Answer 2

However, if you have maximum Qty's are known which are in comma separated format then you could use xml node method to separate them into columns.QTY1...QTY5
SELECT DISTINCT ID, ITEMQTY,
a.value('/A[1]', 'VARCHAR(MAX)') as QTY1,
a.value('/A[2]', 'VARCHAR(MAX)') as QTY2,
a.value('/A[3]', 'VARCHAR(MAX)') as QTY3,
a.value('/A[4]', 'VARCHAR(MAX)') as QTY4,
a.value('/A[5]', 'VARCHAR(MAX)') as QTY5
FROM
(
SELECT ID, ITEMQTY,
CAST('<A>'+REPLACE(ITEMQTY, ',', '</A><A>')+'</A>' AS XML) AS ITEMQTY1
FROM inputTable
) A
CROSS APPLY ITEMQTY1.nodes('/A') AS split(a);
Result :
ID ITEMQTY QTY1 QTY2 QTY3 QTY4 QTY5
1 a,b,c a b c NULL NULL
2 x,y x y NULL NULL NULL
3 l,m,n,o,p l m n o p
4 a,b a b NULL NULL NULL
5 m m NULL NULL NULL NULL
Later, you could replace null by using coalesce() or isnull() function with ''

Answer 3

Use This
First Create a function
CREATE FUNCTION [dbo].[fn_split](
#str VARCHAR(MAX),
#delimiter CHAR(1)
)
RETURNS #returnTable TABLE (idx INT PRIMARY KEY IDENTITY, item VARCHAR(8000))
AS
BEGIN
DECLARE #pos INT
SELECT #str = #str + #delimiter
WHILE LEN(#str) > 0
BEGIN
SELECT #pos = CHARINDEX(#delimiter,#str)
IF #pos = 1
INSERT #returnTable (item)
VALUES (NULL)
ELSE
INSERT #returnTable (item)
VALUES (SUBSTRING(#str, 1, #pos-1))
SELECT #str = SUBSTRING(#str, #pos+1, LEN(#str)-#pos)
END
RETURN
END
GO
and use function like this
Declare #test TABLE (
ID VARCHAR(200),
Data VARCHAR(200)
)
insert into #test
(ID, Data)
Values
(1,'a,b,c')
insert into #test
(ID, Data )
values(2,'x,y')
insert into #test
(ID, Data )
values(3,'l,m,n,o,p')
insert into #test
(ID, Data )
values(4,'a,b')
insert into #test
(ID, Data )
values(5,'m')
select ID,data AS ItemQty,
ISNULL((select item from fn_split(Data,',') where idx in (1)),'') as QTY1 ,
ISNULL((select item from fn_split(Data,',') where idx in (2)),'') as QTY2,
ISNULL((select item from fn_split(Data,',') where idx in (3)),'') as QTY3,
ISNULL((select item from fn_split(Data,',') where idx in (4)),'') as QTY5 ,
ISNULL((select item from fn_split(Data,',') where idx in (5)),'') as QTY5
from #test
Output Same as your Image
instead of using
insert into #test
(ID, Data)
Values
(1,'a,b,c')
you can also assgin it like this
insert into #test
(ID, Data)
Values
(Select Column1, Column2 From YourTable)