Unused table alias SQL-L025
Anti-pattern
Major
Tables should not be aliased if that alias is not used. An usused alias makes code harder to read without changing any functionality.
Duplicate table aliases SQL-L020
Anti-pattern
Critical
Table aliases should be unique within each clause. It is recommended to name the aliases differently.
Column expression without alias detected SQL-L013
Anti-pattern
Major
It is recommended to use explicit AS clause for column expressions.
DISTINCT with parenthesis SQL-L015
Anti-pattern
Major
Parenthesis are not needed and confuse DISTINCT with a function. The parethesis can also be misleading in which columns they apply to.
Ambiguous use of DISTINCT SQL-L021
Anti-pattern
Major
Ambiguous use of DISTINCT in select statement with GROUP BY.
Subquery found in JOIN SQL-L042
Anti-pattern
Minor
JOIN clauses should not contain subqueries. Use Common Table Expression(CTE, aka WITH statement)s instead.
Unflattened CASE statements in ELSE clause SQL-L058
Anti-pattern
Minor
Nested CASE statement in ELSE clause could be flattened.
Unknown number of resulting columns SQL-L044
Anti-pattern
Minor
Queries that produce an unknown number of result columns are an anti-pattern.