Create temp table from provided variable column names - sql

Question

I want to create a temporary table, in which the columns will be those which I provide as parameter, separated by a delimiter.
For example, if the column names are: id, name, address..the respective table should contain the same amount and header names of the columns. Similarly, next time the column number and names could vary.
Any help in this regard?

Answer 1

Try this :-
CREATE PROCEDURE GenerateTempTable
#tableName as nvarchar(max),
#Col1 as nvarchar(255),
#Col2 as nvarchar(255)
AS
BEGIN
Declare #sql nvarchar(max)
set #sql='CREATE TABLE #'+ #tableName + '
('+ #col1+ ' nvarchar(255),'+
#col2 + ' nvarchar(255)
)'
-- Select #sql Check the DDL
EXECUTE sp_executesql #sql,
N'#tableName nvarchar(max),#Col1 nvarchar(255),#Col2 nvarchar(255)',
#tableName = #tableName,#Col1=#Col1,#Col2=#Col2
END
The problem with the above query is temp table is created with the dynamic block query therefore it cannot be accessed after the block . In order to access the table outside the scope then you need to create global temp table ##
Edit :-
An example with Global Temp Tables and static table name
ALTER PROCEDURE GenerateTable
#Col1 as nvarchar(255),
#Col2 as nvarchar(255)
AS
BEGIN
Declare #sql nvarchar(max)
If object_id('tempdb..##TempTable') is not null
Drop table ##TempTable
set #sql='CREATE TABLE ##TempTable
('+ #col1+ ' nvarchar(255),'+
#col2 + ' nvarchar(255)
)'
-- Select #sql Check the DDL
EXECUTE sp_executesql #sql,
N'#Col1 nvarchar(255),#Col2 nvarchar(255)',
#Col1=#Col1,#Col2=#Col2
END
To execute the SP the sql is :-
Declare #tableName varchar(max),
#Col1 varchar(70),
#Col2 varchar(70)
Exec GenerateTable #col1='ColA',#Col2='ColB'
Edit 2:-
If you are sure that the number of parameters wont exceed x values ( Say 5) .Then you can create 5 default parameter .Check this link for further details.

Answer 2

Could you not build a table out of a distinct list from wherever these "Dynamic Field Names" live... Then push that in as a string list... Like... I built a table with colors then got a field of names and now am going to push it into a string that can be used to build out the table headers... no limit to quantity...
SELECT #Fields = coalesce(#Fields + ',', '') + convert(varchar(50),[name])
FROM #TempCols
WHERE column_id > 1
ORDER BY column_id
Where Column_ID is just a Windowed ROW_Number...
I don't agree with the notion of its not possible ever. There is always a way, we may not see it now but there is always a method that can be nested or abused to bend any rule to what we need.