Adam Heath-2 wrote:
>
>> If we can provide a generic solution, this will be a good add-on. Please
>> share your views.
>
> Is it possible that some jdbc metadata parameter can specify whether
> the database supports this?
>
The patch contains a parameter:
+ use-order-by-nulls="true">
for this purpose. For the databases listed it will generate a database
native "NULLS FIRST/LAST" statement as part of the order by clause. For the
other databases (the ones where this property is not set or is set to
"false") it will generate a case:
+ if ((nullsFirst != null) && (!datasourceInfo.useOrderByNulls)) {
+ sb.append("CASE WHEN ");
+ getValue().addSqlValue(sb, modelEntity, null,
includeTablenamePrefix, datasourceInfo);
+ sb.append(" IS NULL THEN ");
+ sb.append(nullsFirst ? "0" : "1");
+ sb.append(" ELSE ");
+ sb.append(nullsFirst ? "1" : "0");
+ sb.append(" END, ");
+ }
+
It should be noted that this generation only occurs if the "nulls" is
explicitly specified on the order-by clause. I thought about always
generating this snippet to support a "default sorting behaviour" across all
databases, but I did not want to alter existing sql statements without a
discussion on that. So with this patch one can explicitly specify how they
want nulls sorted and it should work for all databases.
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