Put numbers for each rows in STRING_AGG in SQL Server - sql

Question

I have to put some columns and group them together by STRING_AGG also I want to put number first of each rows
What I have:
Name
Cake
Coca
ice-cream
Same
one
five
six
Sara
one
one
NULL
John
two
two
NULL
I want the output be something like this:
Name
Description
Sam
1.two 2.five 3. six
Sara
1.one 2.one
John
1.two 2.two
My Code:
SELECT Name, STRIN_AGG(CONCAT(Cake, ' ,', Coca,' ,', ice-cream))
FROM FoodTable
but I do not know how to consider numbers first of each rows in STRING_AGG

Answer 1

You don't need string_agg():
select name,
concat('1.' + cake, ' 2.' + coca, ' 3.' + ice_cream)
from t;
Note that + returns NULL if any value is NULL. However, concat() simply ignores NULL values.
If you really, really wanted to use string_agg() you could:
select t.name, v.all_together
from t cross apply
(select string_agg(v.n + v.val, ' ') within group (order by v.n) as all_together
from (values ('1.', t.cake),
('2.', t.coca),
('3.', t.ice_cream)
) v(n, val)
) v;

Answer 2

Here is a complete dynamic sql approach. No need to serialize and deserialize the data using XML or JSON. In this case the list of food items is contained in a temporary table so it reads the column names from tempdb.sys.columns.
The query uses CROSS APPLY to unpivot the columns (of food items) and assigns a ROW_NUMBER() to each non NULL item value. Something like this
drop table if exists #FoodTable;
go
create table #FoodTable(
[Name] varchar(100) not null,
Cake varchar(100) null,
Coca varchar(100) null,
[ice-cream] varchar(100) null);
--select * from dbo.test_actuals
insert #FoodTable values
('Sam', 'one', 'five', 'six'),
('Sara', 'one', 'one', null),
('Jon', 'two', 'two', null);
;with unpvt_cte([Name], item, val, rn) as (
select f.[Name], v.*, row_number() over (partition by [Name] order by (select null))
from #FoodTable f
cross apply (values ('Cake', Cake),
('Coca', Coca),
('IceCream', [ice-cream])) v(item, val)
where v.val is not null)
select [Name], string_agg(concat(rn, '.', val), ' ') within group (order by rn) answer
from unpvt_cte
group by [Name];
Name answer
Jon 1.two 2.two
Sam 1.one 2.five 3.six
Sara 1.one 2.one
to make the query dynamic
declare #food_list nvarchar(max);
select #food_list=string_agg(quotename(concat_ws(',', quotename(sysc.[name], ''''),
quotename(sysc.[name], '[]')), '()'), ',')
from tempdb.sys.columns sysc
where object_id = Object_id('tempdb..#FoodTable')
and [name]<>'Name';
declare
#sql_prefix nvarchar(max)=N'
;with unpvt_cte([Name], item, val, rn) as (
select f.[Name], v.*, row_number() over (partition by [Name] order by (select null))
from #FoodTable f
cross apply (values ',
#sql_suffix nvarchar(max)=N'
) v(item, val)
where v.val is not null)
select [Name], string_agg(concat(rn, ''.'', val), '' '') within group (order by rn) answer
from unpvt_cte
group by [Name];';
declare
#sql nvarchar(max)=concat(#sql_prefix, #food_list, #sql_suffix);
print(#sql);
exec sp_executesql #sql;
The print statement outputs the following
;with unpvt_cte([Name], item, val, rn) as (
select f.[Name], v.*, row_number() over (partition by [Name] order by (select null))
from #FoodTable f
cross apply (values ('Cake',[Cake]),('Coca',[Coca]),('ice-cream',[ice-cream])
) v(item, val)
where v.val is not null)
select [Name], string_agg(concat(rn, '.', val), ' ') within group (order by rn) answer
from unpvt_cte
group by [Name];

Answer 3

You may use a union to acquire the numbers for each column. Here I've used a cte but you could have used a subquery. Each query in the union renames the food type column to food and adds a column num that will be used in the final query. In the final query the where clause filters NULL foods and a group by with the string_agg and concat is used to retrieve the data in the desired format. I've included a working fiddle below:
WITH FoodTableNums AS (
SELECT Name, Cake as food, 1 as num FROM FoodTable UNION ALL
SELECT Name, Coca as food, 2 as num FROM FoodTable UNION ALL
SELECT Name, icecream as food, 3 as num FROM FoodTable
)
SELECT
Name,
STRING_AGG(CONCAT(num,'.', food),',' ) WITHIN GROUP( ORDER BY num asc) as Description
FROM
FoodTableNums
WHERE
food IS NOT NULL
GROUP BY
Name
Name
Description
John
1.two,2.two
Sam
1.one,2.five,3.six
Sara
1.one,2.one
db<>fiddle here
Let me know if this works for you.

Answer 4

Here is an option that is a bit more dynamic. You only have to Exclude certain columns ... in this case NAME
We use a bit of JSON to dynamically UNPIVOT the row, and then string_agg() to consolidate.
Example or dbFiddle
Select A.Name
,B.NewValue
From YourTable A
Cross Apply (
Select NewValue=STRING_AGG(concat(Seq,'.',Value),' ') within group (order by Seq)
From (
Select [Key]
,[Value]
,[Seq] = row_number() over (order by ##spid)
From OpenJson( (Select A.* For JSON Path,Without_Array_Wrapper ) )
Where [Key] not in ('Name')
) B1
) B
Results
Name NewValue
Same 1.one 2.five 3.six
Sara 1.one 2.one
John 1.two 2.two

Answer 5

Here is s generic way regardless of how many columns in a table.
It is based on XML/XQuery.
No need to UNPIVOT the rows, and then STRING_AGG() to consolidate.
All data in each row stays in a row.
SQL
-- DDL and data population, start
DECLARE #tbl table (
[Name] varchar(100) not NULL PRIMARY KEY,
Cake varchar(100) null,
Coca varchar(100) null,
[ice-cream] varchar(100) null);
INSERT #tbl VALUES
('Sam', 'one', 'five', 'six'),
('Sara', 'one', 'one', null),
('Jon', 'two', 'two', null);
-- DDL and data population, end
SELECT p.[Name]
, x.query('
for $r in /root/*[local-name()!="Name"]/text()
let $pos := count(root/*[. << $r]) - 1
return concat(string($pos), ".", $r)').value('text()[1]', 'VARCHAR(MAX)') AS Result
FROM #tbl AS p
CROSS APPLY (SELECT * FROM #tbl AS c
WHERE c.[Name] = p.[Name]
FOR XML PATH(''), TYPE, ROOT('root')) AS t(x);
Output
+------+--------------------+
| Name | Result |
+------+--------------------+
| Jon | 1.two 2.two |
| Sam | 1.one 2.five 3.six |
| Sara | 1.one 2.one |
+------+--------------------+

Answer 6

Although I agree with those saying that it would be much better to normalise your tables, but if you can't do that then this proposal makes GGordon's solution dynamic, building an SQL statement that retrieves all the columns on your FoodTable. No matter if they are 3 or 100 food columns.
CREATE TABLE FoodTable (
Name VARCHAR(4),
Cake VARCHAR(3),
Coca VARCHAR(4),
icecream VARCHAR(4)
);
INSERT INTO FoodTable ("Name", "Cake", "Coca", "icecream")
VALUES ('Sam', 'one', 'five', 'six'),
('Sara', 'one', 'one', NULL),
('John', 'two', 'two', NULL);
declare #SQL nvarchar(max);
WITH Food As (
SELECT ORDINAL_POSITION - 1 AS Num, COLUMN_NAME AS Food
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = N'FoodTable' AND COLUMN_NAME <> 'Name'
)
SELECT #SQL = N'WITH FoodTableNums AS ( ' +
string_agg('SELECT Name, ' + Food + ' as Food, ' + convert(varchar(20), Num) + ' as Num FROM FoodTable', ' UNION ALL ') +
') SELECT Name, STRING_AGG(CONCAT(num,''.'', food),'','' ) WITHIN GROUP( ORDER BY num asc) as Description FROM FoodTableNums WHERE food IS NOT NULL GROUP BY Name'
FROM Food;
EXECUTE sp_ExecuteSQL #SQL;
You can see it working here : Fiddle