Hi Chris/Tom,

CREATE TABLE alias_test AS
SELECT level x, 'test'||to_char(level) y from dual connect by level <=10
/
select x, y from alias_test
/
select x y from alias_test

Y
--
1
2
3
...

It is a user mistake of not separating the columns of a table by comma operator(,) , instead oracle treats it as an alias.
So the values for x are shown as Y (which is another column of the same table) .
Here the table contained only two columns and we fix the issue.

If suppose table contains say 60 columns, and in the select query we had missed a comma(,) by mistake for one the columns,
then the value of a given column will be treated as the value of another column, some-times this causes a blunder, since
logic would have written assuming the column values.

I agree it is completely user's mistake, but I think oracle knows that it is the same column of the referenced table,
why oracle cannot throw a WARNING before executing the sql statement, that the another column of the same table has been
referenced as an alias in the sql statement.

Basically, I am looking for WARNINGs FOR SQL STATEMENT EXECUTION SIMILAR TO PL/SQL/PACKAGE/PROCEDURE/FUNCTION BLOCK EXECUTION.
Currently as of 12c, is there any way to identify such mistakes/get COMPILER WARNINGS for SQL statements?


Thanks,
Raghavendra B