little error in mysql query

Question

Can someone please help me in this minute error. I wrote this, (which is not working),

SELECT sum(case when SD.order_id>0 then 1 else 0 end) as SD.customer_id  
FROM tbl_order_lead_send_detail SD

but, this query is working fine.

SELECT sum(case when order_id>0 then 1 else 0 end) as customer_id  
FROM tbl_order_lead_send_detail

Answer 1

Please try:

SELECT sum(case when SD.order_id>0 then 1 else 0 end) as customer_id FROM tbl_order_lead_send_detail, SD

Answer 2

You problem is this:

as SD.customer_id 

You might consider writing:

as `SD.customer_id` 

EDIT

Becuase you cannot have . in the column names. If you have them as a string it works. The . is used for columns in tables.