Re: How do I write a "tally" query in SQL?

Now that I'm embarassed for not having remembered how to do the simple case, let me further embarass myself by asking how to do a slightly more complex case. Say the initial table looks like this:

        Firstname  Lastname  Order
        ---------  --------  -----
        JOHN       SMITH     10001
        JOHN       SMITH     10002
        JOHN       SMITH     10003
        TIM        JONES     10004
        TIM        JONES     10005
        TIM        JONES     10006
        TIM        JONES     10007
        JAMES      DOE       10008
        JAMES      DOE       10009

I want to generate this output:

        Firstname  Lastname  Tally
        ---------  --------  -----
        JOHN       SMITH     3
        TIM        JONES     4
        JAMES      DOE       2

I don't understand the ORA-973 error I'm getting, and I have no reference material to look it up in:

  SQL> select firstname, lastname, count(lastname) from users;   select firstname, lastname, count(lastname) from users

*

  ERROR at line 1:
  ORA-00937: not a single-group group function

  SQL> select firstname, lastname, count(*) from users;   select firstname, lastname, count(*) from users

*

  ERROR at line 1:
  ORA-00937: not a single-group group function

  SQL> select firstname, lastname, count(firstname) from users;   select firstname, lastname, count(firstname) from users

*

  ERROR at line 1:
  ORA-00937: not a single-group group function

What's the syntax I'm looking for? Also, are there any good SQL language references on the web? (AltaVista wasn't able to find anything useful.)

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