why is this query invalid?

Question

Why is this query invalid? When I write just SRV_ID instead of vt_exam_details.SRV_ID everything works just fine

 cl_id
, cl_name_last as CUSTOMER
, vt_animals.an_type
, vt_exam_details.SRV_ID
, vt_services.srv_desc
, vt_exam_details.ex_fee
from vt_clients
join vt_animals using (cl_id)
join vt_exam_headers using (an_id)
join vt_exam_details using (ex_id)
join vt_services using (srv_id)

Error:

Error at Command Line:5 Column:3
Error report:
SQL Error: ORA-00904: "VT_EXAM_DETAILS"."SRV_ID": invalid identifier
00904. 00000 - "%s: invalid identifier"
*Cause: 
*Action:

Thanks.

• Marc B: is vt_exam_details the right table for SRV_ID?
• Ahmad: well.your error says that..the table vt_exam_details doesn't have any column named "SRV_ID".
• user2079915: SQL> describe vt_exam_details EX_ID NOT NULL NUMBER(6) LINE_ITEM NOT NULL NUMBER(6) SRV_ID NOT NULL NUMBER(6) EX_FEE NOT NULL NUMBER(6,2) EX_DESC VARCHAR2(50) }
• user2079915: I'm sorry, I'm new here, so writing a little messy. as you can see I have that srv_id

Answer 1

Because the table vt_exam_details is not in the FROM clause?

• user2079915: but my other tables are not in the FROM clause either
• Vaishak Suresh: Could you post the columns in the table? easier to help that way. Also, could the case be different for the column names?
• user2079915: SQL> describe vt_exam_details EX_ID NOT NULL NUMBER(6) LINE_ITEM NOT NULL NUMBER(6) SRV_ID NOT NULL NUMBER(6) EX_FEE NOT NULL NUMBER(6,2) EX_DESC VARCHAR2(50) } –
• user2079915: I think the answer is that, since I have join vt_services using (srv_id) I don't have to specify the table name for attribute srv_id
• Vaishak Suresh: Exactly! otherwise you would get error for vt_exam_details.ex_fee too.

Answer 2

Is there a SRV_ID in table VT_EXAM_DETAILS?

• user2079915: SQL> describe vt_exam_details EX_ID NOT NULL NUMBER(6) LINE_ITEM NOT NULL NUMBER(6) SRV_ID NOT NULL NUMBER(6) EX_FEE NOT NULL NUMBER(6,2) EX_DESC VARCHAR2(50) } –
• user2079915: I think the answer is that, since I have join vt_services using (srv_id) I don't have to specify the table name for attribute srv_id