Is there any equivalent to Postgresql EVERY aggregate function on other RDBMS?

Question

Documentation for EVERY aggregate:

every(expression) : true if all input values are true, otherwise false

http://www.postgresql.org/docs/9.1

Answer 1

Emulating EVERY() with CASE and SUM()

In fact, this article describes how EVERY() can be emulated via CASE and SUM(). The following two statements are equivalent:

SELECT EVERY(id < 10)
FROM book

SELECT CASE SUM(CASE WHEN id < 10 THEN 0 ELSE 1 END) 
         WHEN 0 THEN 1 
         ELSE 0 
       END
FROM book;

The same is true for the EVERY() window function:

SELECT 
  book.*, 
  EVERY(title LIKE '%a') OVER (PARTITION BY author_id)
FROM book

SELECT
  book.*,
  CASE SUM(CASE WHEN title LIKE '%a' THEN 0 ELSE 1 END)
       OVER(PARTITION BY author_id)
    WHEN 0 THEN 1 
    ELSE 0
  END
FROM book;

SQL Standard

The SQL:2008 standard mentions the EVERY aggregate function:

10.9 

[...]

 ::=
  COUNT    [  ]
  |  [  ]
  |  [  ]
  |  [  ]

 ::=
    [  ]
   

 ::=
  

 ::=
  AVG
  | MAX
  | MIN
  | SUM
  | EVERY
  | [...]

But "advanced" SQL standard features are not often implemented by databases. Oracle 11g for instance, doesn't support it, neither does SQL Server 2012.

With HSQLDB, however, you may be more lucky. HSQLDB 2.x is very standards-compliant, also MySQL knows the BIT_AND() aggregate function, which is a non-standard alias to EVERY(), also supported by Postgres.

Note, some databases allow for writing user-defined aggregate functions, so you may as well implement EVERY() yourself.