Extracting All Columns, Including ROWNUM
In Oracle, retrieving all columns and an additional ROWNUM is essential for various scenarios. Initially, it might seem challenging to retrieve all columns without explicitly naming them. However, a straightforward technique can achieve this:
Use the qualified "*" syntax:
SELECT rownum, table.* FROM table;
By appending ". *" to the table name, the query will implicitly include all columns in the result set, including the ROWNUM pseudo-column. This approach ensures that all table columns are returned, dynamically adapting to any schema changes.
For instance, if the "table" contains columns "column1," "column2," and "column3," the query will produce a result similar to:
**ROWNUM** **COLUMN1** **COLUMN2** **COLUMN3** 1 Joe Smith 1 2 Bob Jones 3
This method provides a concise and effective way to retrieve all columns in a table, simplifying the process and improving code maintainability.
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