recursive ANSI99 union?

[Stefa Biadji]

Hi,
Does some version of MSSQL supports ANSI 99 (SQL 3) syntax for recursive
SQL unions?
Stefan Boiadjiev

[Joe Celko]

Nope. Try DB2 and their WITH operator.

If you are trying to model a tree structure, there are other methods.

--CELKO--
===========================
Please post DDL, so that people do not have to guess what the keys,
constraints, Declarative Referential Integrity, datatypes, etc. in your
schema are.

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[Daniel Morgan]

Joe Celko wrote:

Is this the same functionality provided by Oracle with CONNECT BY?

Daniel Morgan

[Joe Celko]

>> Is this the same functionality provided by Oracle with CONNECT BY? <<

No, the CONNECT BY is a hidden cursor used for doing a tree tarversal in
the adjacency model. Very limited, very slow, and non-relational.

The WITH [RECURSIVE] clause is reallllly complex in full SQL-99. You
set up a synonym for an expression and that synonym can be used inside
the expresion to get recursion. this one is a "read a book" kind of
animal.

I think it is one of the worst parts of SQL-99 because of the complexity
of it. And one of the reasons people do not want to implement or move
to SQL-99.

[Daniel Morgan]

Joe Celko wrote:

Thanks,

Daniel Morgan