This error is typical of a situation where you are attempting to create a view without 
specifying the column names after the view name, but you are relying on the column name 
or the column alias specified in the query, as in this example:
 
 
CREATE VIEW test_v AS
SELECT owner || '.' || table_name
FROM all_tables
WHERE owner = USER;

ORA-00998: must name this expression with a column alias
The error is easily fixed as follows:


 
CREATE OR REPLACE VIEW test_v AS
SELECT owner || '.' || table_name AS qualified_table_name
FROM all_tables
WHERE owner = USER;
or in this other equivalent way:
CREATE OR REPLACE VIEW test_v (qualified_table_name)
AS
SELECT owner || '.' || table_name
FROM all_tables
WHERE owner = USER;
 

Getting following ora error code :

ORA-00998: must name this expression with a column alias

when trying to create this query

CREATE OR REPLACE VIEW PARTNER_SUMMARY_SEEMORE_VW
AS
SELECT PARTNER,
       TO_CHAR (SUM(TOTAL)) as TOTAL,
         TO_CHAR (SUM(ORG_SENT)) as ORG_SENT,
          TO_CHAR (SUM(ORG_RECEIVED)) as ORG_RECEIVED,
          TO_CHAR (SUM(TAX_RTN_PROCESSED)) as TAX_RTN_PROCESSED,
          TO_CHAR (SUM(TAX_RTN_REVIEWED)) as TAX_RTN_REVIEWED,
           TO_CHAR (SUM(TAX_RTN_SENT_TO_TAXPAYER)) as TAX_RTN_SENT_TO_TAXPAYER,
        office_name as office_name,
            TO_CHAR(NULL)
FROM PARTNER_SUMMARY_VW
 GROUP BY partner,office_name
UNION ALL
 SELECT total_text,
force_bold_fn(a) as a,
force_bold_fn(TOTAL_ORG_SENT) as TOTAL_ORG_SENT,
force_bold_fn(TOTAL_ORG_RECEIVED) as TOTAL_ORG_RECEIVED,
force_bold_fn(TOTAL_ORG_PROCESS) as TOTAL_ORG_PROCESS,
force_bold_fn(TOTAL_ORG_REVIEW) as TOTAL_ORG_REVIEW,
force_bold_fn(TOTAL_ORG_CLIENT) as TOTAL_ORG_CLIENT,
TO_CHAR(NULL),
force_bold_fn(TOTAL_ORG_PARTNER) as TOTAL_ORG_PARTNER
FROM gts_totals_vw

and I got the above error

I tried giving a alias for the columns ctype , btext .. but helpless. which column to be aliased ?

Oracle Error :: ORA-00998

must name this expression with a column alias

Cause

An expression or function was used in a CREATE VIEW statement, but no corresponding column name was specified. When expressions or functions are used in a view, all column names for the view must be explicitly specified in the CREATE VIEW statement.

Action

Enter a column name for each column in the view in parentheses after the view name.