Updated November, 23 2023
SQL Aliases#
For each subquery, we add an alias if it doesn’t exist.
DTA$<index>
1--Oracle
2SELECT 1 FROM (SELECT 1 FROM DUAL);
3
4
5--PostgreSQL:
6SELECT 1 FROM (SELECT 1 FROM DUAL) DTA$1;
We add AS keyword before SELECT item alias if it was missed.
1--Oracle
2SELECT 1 ONE FROM DUAL;
3
4
5--PostgreSQL
6SELECT 1 AS ONE FROM DUAL;
Issues
For missed select item aliases we should add aliases with names equal to the select item expression.