Delete duplicates

[luiddog]

I have an user DB and I need to delete all the rows with duplicate emails, excluding rows where the address is not null. But I don't want to delete every entry I want to keep one entry per an email address.

So if I had:

User: tom
Email: [e-mail]
Address:

User: tom2
Email: [e-mail]
Address: 123 fake

User: tom3
Email: [e-mail]
Address:

User: dick
Email: [e-mail]
Address:

User: dick2
Email: [e-mail]
Address:

User: harry
Email: [e-mail]
Address:

And I want

User: tom2
Email: [e-mail]
Address: 123 fake

User: dick2
Email: [e-mail]
Address:

User: harry
Email: [e-mail]
Address:

Or I want

User: tom3
Email: [e-mail]
Address:

User: tom2
Email: [e-mail]
Address: 123 fake

User: dick2
Email: [e-mail]
Address:

User: harry
Email: [e-mail]
Address:

[joe2]

Create a temp table.. dump the required data in temp table. delete entry from original table. then dump data from temp table to original table.