On Wednesday, 28 March 2018 00:11:29 UTC+8, Wes Clark wrote:
>
> We switched to Oracle mode so that unique indexes could allow multiple 
> null values.  Is there a way to preserve that and still use the H2 date 
> datatype?
>

In regular mode unique indexes allow multiple rows with NULL values too. 
They are forbidden only in HSQLDB, Derby, and MSSQLServer modes.

But if you use multi-column indexes there is a difference between regular 
and Oracle mode.

In Oracle mode only rows with NULL values in all indexed columns may be 
duplicated.
IDX_COL1  IDX_COL2
null      null
null      null

In regular mode rows with NULL value in any indexed column may be 
duplicated.
IDX_COL1  IDX_COL_2
null      null
null      null
null      value1
null      value2
value3    null
value4    null

-- 
You received this message because you are subscribed to the Google Groups "H2 
Database" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/h2-database.
For more options, visit https://groups.google.com/d/optout.

Reply via email to