Grokbase Groups Cayenne dev June 2015

On Mon, Jun 15, 2015 at 10:16 AM Andrus Adamchik wrote:

Hi John,

IIRC you can force PostgreSQL (or any other DB really) to treat column
names as case-sensitive by including them in double quotes when creating
and querying the tables. In Cayenne this means setting "Quote SQL
Identifiers" to "on" in the DataMap and using explicit double quotes in

Not going to help with "SELECT * FROM", but should address all other cases.
I definitely don't want my DB to be case sensitive, or to make my all my
SQL statements much longer by adding quotes everywhere.

Like forcing or providing a switch to ensure DbAttribute names are
If the above doesn't help, you can probably decorate DataMapLoader service
to conditionally convert loaded DataMap to lower case DbAttributes (if you
can access DataSource and determine DB type prior to project loading), or
do that in the EntityResolver after ServerRuntime startup (less clean, but
same end result).
I've addressed it in my project by doing this. If that's going to be the
recommended solution it should be part of the library. The code to switch
everything to lowercase is a bit involved. I wonder if it would be
reasonable to detect the DB and do this automatically?

The specific problem I ran into is this: in ObjectResolver.createObjectId
there is this:

             Object val = dataRow.get(key);
             // this is possible when processing left outer joint prefetches
             if (val == null) {
                 return null;

Since the case doesn't match for the PK null is returned. Making this
fallback to a case-insensitive lookup would help a bit. However, all the
columns have this problem, not just the PKs. The difference the PK columns
are more likely to be defined in mixed case because they are generated into
java source as the PK_COLUMN constant and mixed case is necessary for a
good name to be generated.


On Jun 13, 2015, at 12:13 AM, John Huss wrote:

I've run into problems a few times caused by case-mismatch issues with
columns (DbAttributes).

The primary one being when I have SQLTemplate queries that return actual
DataObjects. If the DbAttribute is declared with mixed case (myTablePK)
then my query just returns a list of nulls because it can't find the pk
field to create an ObjectId. I'm using postgres mostly which is not
case-sensitive and returns the columns in lowercase it seems.

What do you think about changing some of this behavior?

Like forcing or providing a switch to ensure DbAttribute names are

Or doing more intelligent matching that ignores case as much as possible?
I.E. if there are no duplicate columns when ignoring case, then ignore case?

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postedJun 12, '15 at 9:14p
activeJun 15, '15 at 5:19p

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John Huss: 2 posts Andrus Adamchik: 1 post



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