How to order by dynamic column in TSQL? - sql

Question

I have these tables
CREATE TABLE [dbo].[Columns]
(
[ColumnId] INT,
[TableId] INT NOT NULL,
[ColumnName] NVARCHAR(150) NOT NULL,
[Order] INT,
[Key] BIT
)
CREATE TABLE [dbo].[Tables]
(
[TableId] INT,
[TableName] NVARCHAR(200)
)
CREATE TABLE [dbo].[RowValues]
(
[ColumnId] INT NOT NULL,
[RowNumber] INT NOT NULL,
[Value] NVARCHAR(200) NOT NULL
)
With this sample data:
insert into [Columns] values (1, 1, 'StudentName', 1, 1)
insert into [Columns] values (2, 1, 'Grade', 1, 0)
insert into [Columns] values (3, 1, 'Year', 1, 0)
insert into [Columns] values (4, 1, 'Section', 1, 0)
insert into [Columns] values (5, 2, 'TeacherName', 1, 1)
insert into [Columns] values (6, 2, 'Department', 1, 0)
insert into [Tables] values (1, 'Student')
insert into [Tables] values (2, 'Teacher')
insert into [RowValues] values (1, 1, 'Student Alan')
insert into [RowValues] values (2, 1, '99')
insert into [RowValues] values (3, 1, '1st')
insert into [RowValues] values (4, 1, 'Section 1')
insert into [RowValues] values (1, 2, 'Student Alex')
insert into [RowValues] values (2, 2, '98')
insert into [RowValues] values (3, 2, '1st')
insert into [RowValues] values (4, 2, 'Section 1')
insert into [RowValues] values (1, 3, 'Student Alfonso')
insert into [RowValues] values (2, 3, '97')
insert into [RowValues] values (3, 3, '1st')
insert into [RowValues] values (4, 3, 'Section 1')
insert into [RowValues] values (1, 4, 'Student Ben')
insert into [RowValues] values (2, 4, '96')
insert into [RowValues] values (3, 4, '1st')
insert into [RowValues] values (4, 4, 'Section 1')
insert into [RowValues] values (1, 5, 'Student Cathy')
insert into [RowValues] values (2, 5, '95')
insert into [RowValues] values (3, 5, '1st')
insert into [RowValues] values (4, 5, 'Section 1')
insert into [RowValues] values (5, 1, 'Teacher Tesso')
insert into [RowValues] values (6, 1, 'Biology Dept')
insert into [RowValues] values (5, 2, 'Teacher Marvin')
insert into [RowValues] values (6, 2, 'Math Dept')
I have this stored procedure:
CREATE PROCEDURE [dbo].[usp_DynamicSearch_Paged]
(#searchTerm NVARCHAR(max),
#pageNumber INT = 1,
#pageSize INT = 10,
#sortColumn NVARCHAR(20),
#sortDirection INT)
AS
BEGIN
DECLARE #TableNameLiteral nvarchar(13) = 'TableName'
DECLARE #ColumnNameLiteral nvarchar(10) = 'ColumnName'
IF (ISNULL(#sortColumn, '') = '')
BEGIN
SET #sortColumn = #TableNameLiteral
END
;WITH KeyTableId AS
(
SELECT
T.TableId
FROM
[dbo].[Tables] T
INNER JOIN
[dbo].[Columns] C ON T.TableId = C.[TableId]
WHERE
C.[Key] = 1
), ColumnId AS
(
SELECT
[KeyValue] = C.[ColumnName]
,[ColumnId] = V.[ColumnId]
,V.[Value]
,T.[TableName]
,C.[ColumnName]
,C.[Order]
,C.[Key]
FROM
[dbo].[Tables] T
INNER JOIN
[dbo].[Columns] C ON T.TableId = C.[TableId]
LEFT JOIN
[dbo].[RowValues] V ON V.[ColumnId] = C.[ColumnId]
RIGHT JOIN
KeyTableId KT ON T.TableId = KT.TableId
)
SELECT *
FROM ColumnId
WHERE ISNULL(#SearchTerm,'') = ''
OR [Value] LIKE #SearchTerm + '%'
ORDER BY
CASE WHEN #sortDirection = 2 THEN
CASE
WHEN #sortColumn = #TableNameLiteral THEN [TableName]
WHEN #sortColumn = #ColumnNameLiteral THEN [ColumnName]
END
END DESC,
CASE WHEN #sortDirection = 1 THEN
CASE
WHEN #sortColumn = #TableNameLiteral THEN [TableName]
WHEN #sortColumn = #ColumnNameLiteral THEN [ColumnName]
END
END ASC
OFFSET ((#pageNumber - 1) * #pageSize) ROWS
FETCH NEXT #PageSize ROWS ONLY;
SELECT
ColumnId = C.ColumnId,
C.ColumnName,
C.[Order],
C.[Key]
FROM [dbo].[Tables] T
LEFT JOIN [dbo].[Columns] C ON T.TableId = C.[TableId]
END
Based on the schema you can probably understand what I am trying to build.
My question is how do I order the result based on dynamic name
example (order by "StudentName" DESC)
Expected output
KeyValue ColumnId Value TableName ColumnName Order Key
'StudentName' 1 'Student Cathy' 'Student' 'StudentName' 1 1
'StudentName' 1 'Student Ben' 'Student' 'StudentName' 2 1
'StudentName' 1 'Student Alfonso' 'Student' 'StudentName' 3 1
'StudentName' 1 'Student Alex' 'Student' 'StudentName' 4 1
'StudentName' 1 'Student Alan' 'Student' 'StudentName' 5 1
'Grade' 2 '99' 'Student' 'Grade' 5 0 (Alan's Grade)
'Grade' 2 '98' 'Student' 'Grade' 4 0
... Year
... Section
...
How Do I sort by StudentName or Grade or Section or Year if key = student name
or
Sort by TeacherName or department if key = Teachername
indicated by #sortColumn NVARCHAR(20),
example
declare #SearchTerm NVARCHAR(max)=''
declare #pageNumber INT = 1
declare #pageSize INT = 10
declare #sortColumn NVARCHAR(20) ='StudentName'
declare #sortDirection int= 1 -- 0 asc 1 desc
exec [usp_DynamicSearch_Paged] #SearchTerm, #pageNumber, #pageSize, #sortColumn, #sortDirection