Seagate ST43401N/ND Informazioni Techniche Scaricare il pdf (Pagina 64)

5-10 Implement: Making Required Application Changes

If Your Current Version is 4.x Adaptive Server Enterprise 11.5

or...exists/in/any

Subqueries that contain

exists, in, or any under an or clause nowreturn

correct results sets. SQL Server 4.x did not return rows when a

subquery evaluated to “false”, even if the

or clause was “true”.

You now get correct results without having to write extra code.

This example from pubs2 shows the difference in results when a

query contains

in and a true or clause:

select pub_name

from publishers

where pub_id in

(select pub_id from titles

where title = “No Such Book”)

or pub_id = ‘1389’

>all and <all

Subqueries that contain

>all and <all now return the correct results.

ANSI semantics evaluate these subqueries as “true” when they

match no rows.

This example shows how different releases handle a query that

compares advance amounts paid by a non-existent publisher name:

Release 4.x

Results

Release 10.x and

11.x Results

0736

0877

1389

0736

Release 4.x

Results

Release 10.x and 11.x

Results

NULL Algodata Infosystems

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Seagate ST43401N/ND Informazioni Techniche Pagina 64