Dynamically Create tables and Insert into it from another table with CSV values - sql

Question

Have a Table with the CSV Values in the columns as below
ID Name text
1 SID,DOB 123,12/01/1990
2 City,State,Zip NewYork,NewYork,01234
3 SID,DOB 456,12/21/1990
What is need to get is 2 tables in this scenario as out put with the corresponding values
ID SID DOB
1 123 12/01/1990
3 456 12/21/1990
ID City State Zip
2 NewYork NewYork 01234
Is there any way of achieving it using a Cursor or any other method in SQL server?

Answer 1

There are several ways that this can be done. One way that I would suggest would be to split the data from the comma separated list into multiple rows.
Since you are using SQL Server, you could implement a recursive CTE to split the data, then apply a PIVOT function to create the columns that you want.
;with cte (id, NameItem, Name, textItem, text) as
(
select id,
cast(left(Name, charindex(',',Name+',')-1) as varchar(50)) NameItem,
stuff(Name, 1, charindex(',',Name+','), '') Name,
cast(left(text, charindex(',',text+',')-1) as varchar(50)) textItem,
stuff(text, 1, charindex(',',text+','), '') text
from yt
union all
select id,
cast(left(Name, charindex(',',Name+',')-1) as varchar(50)) NameItem,
stuff(Name, 1, charindex(',',Name+','), '') Name,
cast(left(text, charindex(',',text+',')-1) as varchar(50)) textItem,
stuff(text, 1, charindex(',',text+','), '') text
from cte
where Name > ''
and text > ''
)
select id, SID, DOB
into table1
from
(
select id, nameitem, textitem
from cte
where nameitem in ('SID', 'DOB')
) d
pivot
(
max(textitem)
for nameitem in (SID, DOB)
) piv;
See SQL Fiddle with Demo. The recursive version will work great but if you have a large dataset, you could have some performance issues so you could also use a user defined function to split the data:
create FUNCTION [dbo].[Split](#String1 varchar(MAX), #String2 varchar(MAX), #Delimiter char(1))
returns #temptable TABLE (colName varchar(MAX), colValue varchar(max))
as
begin
declare #idx1 int
declare #slice1 varchar(8000)
declare #idx2 int
declare #slice2 varchar(8000)
select #idx1 = 1
if len(#String1)<1 or #String1 is null return
while #idx1 != 0
begin
set #idx1 = charindex(#Delimiter,#String1)
set #idx2 = charindex(#Delimiter,#String2)
if #idx1 !=0
begin
set #slice1 = left(#String1,#idx1 - 1)
set #slice2 = left(#String2,#idx2 - 1)
end
else
begin
set #slice1 = #String1
set #slice2 = #String2
end
if(len(#slice1)>0)
insert into #temptable(colName, colValue) values(#slice1, #slice2)
set #String1 = right(#String1,len(#String1) - #idx1)
set #String2 = right(#String2,len(#String2) - #idx2)
if len(#String1) = 0 break
end
return
end;
Then you can use a CROSS APPLY to get the result for each row:
select id, SID, DOB
into table1
from
(
select t.id,
c.colname,
c.colvalue
from yt t
cross apply dbo.split(t.name, t.text, ',') c
where c.colname in ('SID', 'DOB')
) src
pivot
(
max(colvalue)
for colname in (SID, DOB)
) piv;
See SQL Fiddle with Demo

Answer 2

You'd need to approach this as a multi-step ETL project. I'd probably start with exporting the two types of rows into a couple staging tables. So, for example:
select * from yourtable /* rows that start with a number */
where substring(text,1,1) in
('0','1','2','3','4','5','6','7','8','9')
select * from yourtable /* rows that don't start with a number */
where substring(text,1,1)
not in ('0','1','2','3','4','5','6','7','8','9')
/* or simply this to follow your example explicitly */
select * from yourtable where name like 'sid%'
select * from yourtable where name like 'city%'
Once you get the two types separated then you can split them out with one of the already written split functions found readily out on the interweb.
Aaron Bertrand (who is on here often) has written up a great post on the variety of ways to split comma delimted strings using SQL. Each of the methods are compared and contrasted here.
http://www.sqlperformance.com/2012/07/t-sql-queries/split-strings
If your row count is minimal (under 50k let's say) and it's going to be a one time operation than pick the easiest way and don't worry too much about all the performance numbers.
If you have a ton of rows or this is an ETL process that will run all the time then you'll really want to pay attention to that stuff.

Answer 3

A simple solution using cursors to build temporary tables. This has the limitation of making all columns VARCHAR and would be slow for large amounts of data.
--** Set up example data
DECLARE #Source TABLE (ID INT, Name VARCHAR(50), [text] VARCHAR(200));
INSERT INTO #Source
(ID, Name, [text])
VALUES (1, 'SID,DOB', '123,12/01/1990')
, (2, 'City,State,Zip', 'NewYork,NewYork,01234')
, (3, 'SID,DOB', '456,12/21/1990');
--** Declare variables
DECLARE #Name VARCHAR(200) = '';
DECLARE #Text VARCHAR(1000) = '';
DECLARE #SQL VARCHAR(MAX);
--** Set up cursor for the tables
DECLARE cursor_table CURSOR FAST_FORWARD READ_ONLY FOR
SELECT s.Name
FROM #Source AS s
GROUP BY Name;
OPEN cursor_table
FETCH NEXT FROM cursor_table INTO #Name;
WHILE ##FETCH_STATUS = 0
BEGIN
--** Dynamically create a temp table with the specified columns
SET #SQL = 'CREATE TABLE ##Table (' + REPLACE(#Name, ',', ' VARCHAR(50),') + ' VARCHAR(50));';
EXEC(#SQL);
--** Set up cursor to insert the rows
DECLARE row_cursor CURSOR FAST_FORWARD READ_ONLY FOR
SELECT s.Text
FROM #Source AS s
WHERE Name = #Name;
OPEN row_cursor;
FETCH NEXT FROM row_cursor INTO #Text;
WHILE ##FETCH_STATUS = 0
BEGIN
--** Dynamically insert the row
SELECT #SQL = 'INSERT INTO ##Table VALUES (''' + REPLACE(#Text, ',', ''',''') + ''');';
EXEC(#SQL);
FETCH NEXT FROM row_cursor INTO #Text;
END
--** Display the table
SELECT *
FROM ##Table;
--** Housekeeping
CLOSE row_cursor;
DEALLOCATE row_cursor;
DROP TABLE ##Table;
FETCH NEXT FROM cursor_table INTO #Name;
END
CLOSE cursor_table;
DEALLOCATE cursor_table;