Displaying SQL SELECT rows in a table display - sql-server

Question

My database structure and sample data:
CREATE TABLE [dbo].[users] (
[user_id] [bigint] IDENTITY(1,1) NOT NULL,
[user_name] [nvarchar](50) NULL,
[first_name] [nvarchar](50) NULL,
[last_name] [nvarchar](50) NULL,
[id_number] [nvarchar](50) NULL,
CONSTRAINT [PK_users] PRIMARY KEY CLUSTERED
(
[user_id] ASC
)
)
insert into users (user_name, first_name, last_name, id_number)
select 'user1','John','Brown',7707071231
union all
select 'user2','Mary','Jane',7303034432
union all
select 'user3','Peter','Pan',5503024441
CREATE TABLE [dbo].[quiz_results] (
[result_id] [bigint] IDENTITY(1,1) NOT NULL,
[quiz_id] [bigint] NOT NULL,
[user_id] [bigint] NOT NULL,
[grade] [bigint] NULL,
CONSTRAINT [PK_quizresults] PRIMARY KEY CLUSTERED
(
[result_id] ASC
)
)
insert into quiz_results (quiz_id, user_id, grade)
select 1,1,88
union all
select 2,1,84
union all
select 3,1,33
union all
select 1,2,65
This query gives me the quiz results for user_id = 1:
SELECT
users.first_name + ' ' + users.last_name + ' (' + users.id_number + ')' AS student_name,
quiz.quiz_name,
quiz_results.grade
FROM quiz_results
INNER JOIN quiz ON quiz_results.quiz_id = quiz.quiz_id
INNER JOIN users ON quiz_results.user_id = users.user_id
WHERE users.user_id = 12345
like this:
+-------------------------+-----------+-------+
| student_name | quiz_name | grade |
+-------------------------+-----------+-------+
| John Brown (7707071231) | quiz a | 88 |
| John Brown (7707071231) | quiz b | 84 |
| John Brown (7707071231) | quiz c | 33 |
+-------------------------+-----------+-------+
But I don't want the student_name shown on each row. I want this output:
+-------------------------+
| John Brown (7707071231) |
+-------------------------+
| quiz a | 88 |
| quiz b | 84 |
| quiz c | 33 |
+-------------------------+
The student_name is on the first row followed by one row for each quiz result - I specifically want the student_name on the first row.
The query will only ever be for one student_name. Essentially, I want to produce a "certificate" directly in the SQL.
What is the best SQL way to get the data into that format? Will a CTE or the STUFF() command work? Or is there a better way?

Answer 1

This simply can't be done in SQL.
SQL can only return scalar values or result sets (tabular data), and result sets don't support "column span" - so the only way to do it is in the presentation layer - but you can do some things in SQL Server to make your job in the presentation layer easier.
One option is to create a stored procedure that will return the student name as an output parameter, and the quiz grades as a result set:
CREATE PROCEDURE GetQuizResultByUserId
(
#UserId int,
#UserName nvarchar(154) OUTPUT
)
AS
-- it's 154 because 50 + 1 + 50 + 2 + 50 + 1
SELECT #UserName = first_name + ' ' + last_name + ' (' + id_number + ')'
FROM users
WHERE user_id = #UserId
SELECT
quiz.quiz_name,
quiz_results.grade
FROM quiz_results
INNER JOIN quiz ON quiz_results.quiz_id = quiz.quiz_id
WHERE quiz_results.user_id = #UserId
GO
Another option, since this is 2016 version, is to return the results as Json, using the For Json clause:
SELECT first_name + ' ' + last_name + ' (' + id_number + ')' As UserName,
(
SELECT quiz.quiz_name,
quiz_results.grade
FROM quiz_results
INNER JOIN quiz ON quiz_results.quiz_id = quiz.quiz_id
WHERE quiz_results.user_id = #UserId
FOR JSON AUTO
) As quizResult
FROM users
WHERE user_id = #UserId
FOR JSON AUTO
The result is the following json:
[
{
"UserName": "John Brown (7707071231)",
"quizResult": [
{
"quiz_name": "quiz a",
"grade": 88
},
{
"quiz_name": "quiz b",
"grade": 84
},
{
"quiz_name": "quiz c",
"grade": 33
}
]
}
]