Check Constraint- Check password contains atleast one number/special Character/uppercase

Question

I'm looking to create three separate check constraints for my SQL Server database to ensure that a password field constrains a minimum of one number, one uppercase character and one special character.

I consider the best way to approach is by creating separate check constrains for example I have created the following constraint to ensure that password length is a minimum of 8

(len([password]) <= (8))

Could any one suggest a way to establish the required validation.

Thanks

Answer 1

You can do this with one constraint, something like:

check password like '%[0-9]%' and password like '%[A-Z]%' and password like '%[!@#$%a^&*()-_+=.,;:'"`~]%' and len(password) >= 8

Just a note about the upper case comparison: this requires that the collation being used be case sensitive. You may need to specify an explicit COLLATE in the comparison to be sure that it is case sensitive.

Answer 2

I did not know answer for your question directly, but after some research i found this methods:

1) Check if given string contains uppercase character

SELECT CASE WHEN BINARY_CHECKSUM([password]) = BINARY_CHECKSUM(LOWER([password])) THEN 0 ELSE 1 END AS DoesContainUpperCase
GO

source: http://www.sqlservercentral.com/Forums/Topic800271-338-1.aspx

2) Check if given string contains at least one special character

We can make simply statement

IF ([password] LIKE '%[^a-zA-Z0-9]%')

source: How to detect if a string contains special characters?

I hope my answer helped you. Kind regards,

Rafal

Answer 3

I had to remove the 'a' in the collection of special characters and added the collate mentioned above. Thanks for your help!

([password] like '%[0-9]%' AND [password] like '%[A-Z]%' collate Latin1_General_BIN2 AND [password] like '%[!@#$%^&*()-_+=.,;:~]%' AND len([password])>=(8))