central attachment/file table design - sql-server

Question

UPDATE:
I have generated below tables from sql server.
here is the screen shots of my design:
shows the data after combining three tables, getting total of 12 rows
my request table has 4 rows and attachment table has 3 rows
CREATE TABLE [dbo].[attachment](
[attach_id] [int] IDENTITY(1,1) NOT NULL,
[process_type_id] [int] NULL,
[attach_content_type] [varchar](100) NULL,
[attach_name] [varchar](100) NULL,
CONSTRAINT [PK_attachment] PRIMARY KEY CLUSTERED
(
[attach_id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
CREATE TABLE [dbo].[process_type](
[process_type_id] [int] IDENTITY(1,1) NOT NULL,
[process_type] [varchar](100) NULL,
CONSTRAINT [PK_process_type] PRIMARY KEY CLUSTERED
(
[process_type_id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
CREATE TABLE [dbo].[request](
[request_Id] [int] IDENTITY(1,1) NOT NULL,
[request_desc] [varchar](200) NULL,
[process_type_id] [int] NOT NULL,
CONSTRAINT [PK_request] PRIMARY KEY CLUSTERED
(
[request_Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
CREATE TABLE [dbo].[request_review](
[review_request_Id] [int] IDENTITY(1,1) NOT NULL,
[review_desc] [varchar](200) NULL,
[process_type_id] [int] NULL,
CONSTRAINT [PK_request_review] PRIMARY KEY CLUSTERED
(
[review_request_Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
I am busy building a database, and now I have a question about my design.
I have got the following tables:
Customer
Employee
upload_doc
I want to be able to add multiple attachments to Customers, Employees
what is the best design:
design #1
Upload_doc
upload_doc_id (NOT auto generated)
upload_doc_name (uploaded doc name)
upload_content_type
upload_doc_data (blob)
employee
employee_id
first_name
middle_name
last_name
upload_doc_id
customer
customer_id
first_name
last_name
upload_doc_id
design #2
Upload_doc
upload_doc_id (AUTO generated)
upload_doc_name (uploaded doc name)
upload_content_type
upload_doc_data (blob)
employee_id
customer_id
employee
employee_id
first_name
middle_name
last_name
customer
customer_id
first_name
last_name

Answer 1

Design one, but would make upload_doc_id an auto gen id column.
If you are using MS SQL, I would use FILETABLE instead of blobs. Files in MS SQL

Answer 2

The info in your question is somewhat limited, but I'll give it a quick attempt. Personally I'd have a common table for personal information like: names and contact info.
Then have a type lookup table that defines what type of person/contact they are: customer / employee.
Then you can link docs to the common person table. Something like the below, which you can run as is:
CREATE TABLE #temp_person -- common information like name & contact info
(
PersonId INT ,
FirstName VARCHAR(20) ,
MiddleName VARCHAR(20) ,
LastName VARCHAR(20) ,
PersonTypeId INT -- lookup value to person type table
)
CREATE TABLE #temp_person_type -- determines if they are employees or customer
(
PersonTypeId INT ,
PersonType VARCHAR(10)
)
CREATE TABLE #temp_employee
(
EmployeeId INT ,
PersonId INT -- linked to person table
-- other fields would be employee specific
)
CREATE TABLE #temp_customer
(
CustomerId INT ,
PersonId INT -- linked to person table
-- other fields would be customer specific
)
CREATE TABLE #temp_upload_doc
(
UploadDocId INT ,
PersonId INT , -- linked to person table
DocName VARCHAR(20)
)
INSERT INTO #temp_person_type
( PersonTypeId, PersonType )
VALUES ( 1, 'Employee' ),
( 2, 'Customer' )
INSERT INTO #temp_person
( PersonId, FirstName, MiddleName, LastName, PersonTypeId )
VALUES ( 1, 'Bob', 'Jon', 'Smith', 1 ),
( 2, 'David', '', 'Jones', 1 ),
( 3, 'Andy', '', 'Johnson', 2 ),
( 4, 'Richard', '', 'Branson', 2 )
INSERT INTO #temp_customer
( CustomerId, PersonId )
VALUES ( 1, 3 ),
( 2, 4 )
INSERT INTO #temp_employee
( EmployeeId, PersonId )
VALUES ( 1, 1 ),
( 2, 2 )
INSERT INTO #temp_upload_doc
( UploadDocId, PersonId, DocName )
VALUES ( 1, 1, 'Doc 1' ),
( 2, 1, 'Doc 2' ),
( 3, 2, 'Doc blah' ),
( 4, 3, 'Doc dog' ),
( 5, 3, 'Doc images' ),
( 6, 4, 'Doc another' ),
( 7, 4, 'Doc la la la' )
-- EMPLOYEES AND DOCS
SELECT *
FROM #temp_person p
INNER JOIN #temp_person_type pt ON pt.PersonTypeId = p.PersonTypeId
INNER JOIN #temp_employee e ON e.PersonId = p.PersonId
INNER JOIN #temp_upload_doc u ON u.PersonId = e.PersonId
WHERE p.PersonTypeId = 1
-- CUSTOMERS AND DOCS
SELECT *
FROM #temp_person p
INNER JOIN #temp_person_type pt ON pt.PersonTypeId = p.PersonTypeId
INNER JOIN #temp_customer c ON c.PersonId = p.PersonId
INNER JOIN #temp_upload_doc u ON u.PersonId = c.PersonId
WHERE p.PersonTypeId = 2
DROP TABLE #temp_customer
DROP TABLE #temp_employee
DROP TABLE #temp_person
DROP TABLE #temp_upload_doc
DROP TABLE #temp_person_type