Signup after validation

I want a signup process based on one required field at signup: (PartnerID)

**Requirement**
 User starts signup by entering a PartnerID during registration.
 If the code exists in a local db table, registration continues and user is activated, otherwise an error message is displayed.

Please advise.
 

CB Query Field can provide that. Create a Text field then under Integrations > CB Query Field > Validation you can turn on custom query based validation. This will let you query against the database to validate the fields value. This lets you supply custom validation error messages as well.

Next how you display this is up to you. You could put your field on a separate tab then set registration layout in CB > Plugin Management > Default > Layout > Registration to be Step by Step. Ensure that tab is ordered first in CB > Tab Management. Now their first step would be to supply that field and they won't be able to continue until its valid. You could use CB Conditional to hide other fields until that field has a value, but that won't check for validity. Personally I'd just have it as your first field and let the rest of the form display as normally.

i have added a text field 'partnerid' but is shows up in the list as 'cb_partnerid' (just wondering).
What could do in the Query field? Is this a SQL query or another CB value? I am not sure.

i have added a text field 'partnerid' but is shows up in the list as 'cb_partnerid' (just wondering).

Custom fields will always prefix with cb_ so yes that's normal.

What could do in the Query field? Is this a SQL query or another CB value? I am not sure.

You'd have to write the SQL to query your external database to verify the value the user supplied, which will be the [value] substitution as shown in the parameters description.

I cannot help you with the SQL as it's your database so I've no idea what the structure could possibly be. Below is an example though that checks if the supplied value matches a username.

Integrations > CB Query Field > Validation
Query Validation: Enable
Query: Validate On: Successful Results
Ajax Validation: Enable

thanks.