Counting Rows that refence another table

Hi,

I have two tables,

Table A(A_ID, Info)

Table B(B_ID, A_ID, Blah) where B.A_ID references A.A_ID

How can I detemine how many records in table B reference each unique A_ID in table A?

I've tried the following but it doesn't work:

Select A.A_ID, COUNT(B.A_ID) FROM A
JOIN B ON A.A_ID = B.A_IDI've figured out the counting using this

Select A.A_ID, COUNT(B.A_ID) FROM A
JOIN B ON A.A_ID = B.A_ID
GROUP BY A.A_ID

Just needed to add the 'group by'

Can anyone tell me how I can restrict this to only show cases where there are (for example) 3 or more records in table B that reference A_ID?|||USE Northwind
GO

SET NOCOUNT ON
CREATE TABLE myTableA(A_Id int)
CREATE TABLE myTableB(B_Id int, A_Id int)
GO

INSERT INTO myTableA(A_Id) SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
INSERT INTO myTableB(B_Id, A_Id)
SELECT 1,1 UNION ALL SELECT 1,2 UNION ALL SELECT 1,3 UNION ALL
SELECT 2,1 UNION ALL SELECT 2,2 UNION ALL
SELECT 3,1
GO

SELECT a.A_Id, COUNT(*)
FROM myTableA a INNER JOIN myTableB b ON a.A_Id = b.B_Id
GROUP BY a.A_Id
GO

SET NOCOUNT OFF
DROP TABLE myTableA, myTableB
GO|||Having Count(*) > 2