How to create a validation rule for 4 picklist values

Question

Hi i am new to salesforce, I want to create a validation rule on an Account object where Picklist field named as Ownership, I want

• that when an user enter no value means null value there should be error
• if user picks a value from picklist then it should save it means no error
• and again if user tries to change the selected picklist, he should be able to do so
• and later I want to bypass this validation rule to System Administrator Profile.

Here is this i have tried.

ISPICKVAL(PRIORVALUE( Ownership ),"Public")  || 
ISPICKVAL(PRIORVALUE( Ownership ),"Private") ||
ISPICKVAL(PRIORVALUE( Ownership ),"Subsidiary") ||  
ISPICKVAL(PRIORVALUE( Ownership ),"Other") ||
ISBlANK(Text(Ownership))

Untill didn't used the Check condition for blank the validation rule was working fine but now on every condition it is giving error.

Answer 1

A better name for validation rules would be invalidation rules because when the formula evaluates to true, it means the rule complains and prevents the invalid data from being saved.

So the key here is to think about what data is invalid. Based on your description so far, that's:

• Picklist cannot be null/blank (it must have a value selected)
• ...if the user's profile is not 'System Administrator' (i.e. allow sysadmins to ignore the rule)

If you wanted nobody to be able to set a null value for a field, you could configure the field to be "required" (no explicit validation rule required there). If you want to make sure that only the configured picklist values can be used, there's a configuration option for that as well (no need to use a validation rule to specify that either).

Once you have a description of what makes a field invalid, it usually translates to a validation rule pretty well. In this case

AND(
    ISBLANK(TEXT(Ownership)),
    $Profile.Name <> 'System Administrator'
)

Everything inside an AND needs to be true for the result to be true. So if Ownership has a value, the validation rule allows the record to save. If the User's profile is Sysadmin, the validation rule will also allow the record to save (even if the picklist is becoming blank).

You may want to consider creating and using a Custom Permission instead of making a carve-out based on user profiles (though exemptions based on profiles are more beginner-friendly I'd argue)