Database Question

[Muriukis]

On 8th I posted a question on Users and pasword. I got an answer but its not
working the way I want. I have 2 tables called Users & UserType
respectively.Usertype can either be an Admin or a User. I have a form where
one enters the users as per their categories which is working well.Now I have
a login form with a Combobox for username and a textbox for password
entry.Previously I had set the passwords in code but since now I have a table
for users I would like to have the user select their usernames from
cboUserName and type their passwords but the application should have a way of
comparing the entered password with the one in the users table.
NB When I use dlookup txtPassword is assigned the value which is not secure
since anyone can select this. I know there is a way to overcome this just not
able to figure it out.
Question 2:
Am using access 2003. How much data can this database hold
because am generating an application that will requare space can a database
in access 2003 hold much data.
Help appreciated
*Dont know and not afraid to ask*

 

[Albert D. Kallal]

NB When I use dlookup txtPassword is assigned the value which is not
secure
since anyone can select this. I know there is a way to overcome this just
not
able to figure it out.

You would likely write some code in the after update event of the text box
(password), the code could look like:

dim strPassWord as string

strPassword = dlookup("PassWord","tblUsers","UserName = '" & me.comboUser &
"'")

if strPassword <> me.txtPassWordTextBoxPromot then

msgbox "password incorrect"

end else

msgbox "password ok"

...code here to open addtional forms, or do whatever you want with a
correct password
end if

You don't mention what version of ms-access. You could consider using the
workgroup security. I don't think it needs to be pointed out that you need
to keep people "out" of that table if it going to be of any type of use in
terms of security. Do you know how to hide the table and ms-access
interface?

Question 2:
Am using access 2003. How much data can this database hold

The size limit of access 2003 is 2 gigs.

So, if you take a average name in a mailing list, add a few extra
fields...your record size might be about 120 characters on average in size.

So, the number of records you can store is:

2 gig = 2,147,483,648 Bytes
1 Character = 1 Byte
120 Characters = 120 Bytes

2 gig / 120 = 32 million records

So, the limit is NOT the number of records..but "how many" records you can
fit into 2 gig.

Of course, if each customer name only takes up 60 characters...then you can
store 64 million records in the file.

So, a file with 100,000 records in ms-access is rater small...

There is no limit on the number of records, but they have to fit within a
2gig space....

 

[John W. Vinson]

On 8th I posted a question on Users and pasword. I got an answer but its not
working the way I want. I have 2 tables called Users & UserType
respectively.Usertype can either be an Admin or a User. I have a form where
one enters the users as per their categories which is working well.Now I have
a login form with a Combobox for username and a textbox for password
entry.Previously I had set the passwords in code but since now I have a table
for users I would like to have the user select their usernames from
cboUserName and type their passwords but the application should have a way of
comparing the entered password with the one in the users table.
NB When I use dlookup txtPassword is assigned the value which is not secure
since anyone can select this. I know there is a way to overcome this just not
able to figure it out.

Well... a home-grown security system like this will keep honest people out,
but anyone with even a modest amount of Access expertise will be able to break
it if they want to. It would actually be easier to download the Access
security whitepaper, study it carefully, and follow the steps in detail; it's
a good checklist, and will let you protect the form and tables better than any
reasonable home-made system.

Microsoft Access 2000 Security FAQ:

http://support.microsoft.com/kb/207793/en-us

Question 2:
Am using access 2003. How much data can this database hold
because am generating an application that will requare space can a database
in access 2003 hold much data.

Two billion bytes in the entire database, though if you need more you can use
multiple backends. For a multiuser database you should certainly use a "split"
database:

http://www.granite.ab.ca/access/splitapp.htm

I know of databases with 20,000,000 rows in the largest table. If you need
more than two gigabytes, consider using an Access frontend to a client/server
database such as SQL/Server or MySQL.

John W. Vinson [MVP]