I have a table with three cols:
Firm No, Date, and Ret.

Code:
Firm No 	Date    	Ret
1		20040101	.01
1		20040102	-.01
1		20040103	.01
1		20040104	.02
2		20040102	.01
2		20040103	-.01
3		20040101	-.02
3		20040102	.05
3		20040103	-.06
3		20040104	.07
4		20040101	-.08
4		20040102	.12
4		20040103	.02

I'd like to select all for the returns for the firms which have observations for each day.

There are a number of ways to get the numbr of days. My fav so far is

SELECT COUNT(DISTINCT date) from myTable;

Which will return the number of days.

So far I have't found a way to get it to let me reutns the firmno, date and rets for those which have all obs

(In this example the return woudl ideally be)
Code:
Firm No 	Date    	Ret
1		20040101	.01
1		20040102	-.01
1		20040103	.01
1		20040104	.02
3		20040101	-.02
3		20040102	.05
3		20040103	-.06
3		20040104	.07
I've tried code like

Code:
SELECT firmno,date,ret,COUNT(*) as numObs
FROM myTable
GROUP BY firmno
HAVING numObs=MAX(numObs)
with no luck (Syntax error).

Any help would be greatly appreciated. Oh, and SQL is MySQL 4.0.18.

Thanks,
Kevin