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Re: [eclipselink-users] Best way to support case insensitive alphanumeric sorting.. 
You can get the type from the mapping for a particular attribute like this:
DirectToFieldMapping dtfMapping = descriptor.getMappingForAttributeName(<directAttributeName>); 
Class mappingType = dtfMapping.getAttributeClassification();

Notice that the type will be a java class rather than a database type.

-Tom

On 11/06/2013 9:45 AM, vaidya nathan wrote:

 From the documentation , I see that we cant use this for non String columns
like say Numeric columns.

For eg, if the column is a numeric , then this will not work ..

Expression  exp = (ascending ? exp.toLowerCase().ascending() :
exp.toLowerCase().descending()) ;

Is there a way in which we can get meta data information about the column and
then have this sort something like

if (column is String)
{
Expression  exp = (ascending ? exp.toLowerCase().ascending() :
exp.toLowerCase().descending()) ;
}
else
{
Expression  exp = (ascending ? exp.ascending() :  exp.descending()) ;
}


Or is there any other way in which we can do this. If possible please furnish me
some  sample codes too or point me to some samples where we are doing this .

Also Dennis you said that didn't work .  Can you elaborate please? What issues
did you have ?

Thx for all your response
Vaidya


On Thu, Jun 6, 2013 at 9:11 AM, Dennis Fuglsang <dennis.fuglsang@xxxxxxxxxx
<mailto:dennis.fuglsang@xxxxxxxxxx>> wrote:

    I had a similar requirement and initially tried using the UPPER operator in
    the ORDER BY clause but that did not work for me.  For example:   "SELECT
    a.ID, a.name <http://a.name> FROM Table a ORDER BY UPPER(a.name
    <http://a.name>)"

    What did work for me was specifying an upper-cased form of the column to
    sort on in the SELECT clause.   For example:   "SELECT a.ID, a.name
    <http://a.name>, UPPER(a.name <http://a.name>) AS name_order FROM Table a
    ORDER BY name_order"



    -----Original Message-----
    From: Tom Ware
    Sent: Thursday, June 06, 2013 9:05 AM
    To: eclipselink-users@xxxxxxxxxxx <mailto:eclipselink-users@xxxxxxxxxxx>
    Subject: Re: [eclipselink-users] Best way to support case insensitive
    alphanumeric sorting..

    EclipseLink provides toUpperCase() and toLowerCase() expressions and JPA
    provides UPPER and LOWER operators.  For queries I expect you could use
    those operators in the ORDER BY part of your query to sort.

    If you are talking about a mapping, you could use an EclipseLink
    DescriptorCustomizer to add ordering by an EclipseLink expression to the
    selection query.  Roughly:

        OneToManyMapping oneToManyMapping =
    (OneToOneMapping)descriptor.getMappingForAttributeName("attributeName");
        ExpressionBuilder builder =
    oneToManyMapping.getSelectionQuery().getExpressionBuilder();
        Expression orderExpression =
    builder.get("postalCode").toLowerCase().ascending();
        oneToManyMapping.getSelectionQuery().addOrdering(orderExpression);

    -Tom
    On 05/06/2013 11:54 AM, vaidya nathan wrote:
     > Hi,
     >
     > What is the best way to support case insensitive alphanumeric sorting
     > using jpa2 and eclipselink ? An example of what i would like to
     > achieve is to sort on something similiar to the canada zips which could
    be alphanumeric..
     >
     > We are using Eclipselinks ReadAllQuery and Expression language to
     > build our queries and the queries that we have so far is like this..
     >
     > SELECT * FROM
     > (SELECT a.*, ROWNUM rnum  FROM
     > (SELECT DISTINCT t1.ID AS a1,<colname>
     >    FROM <Table>  ORDER BY t0.<colname> ASC) a WHERE ROWNUM <= ?) WHERE
    rnum > ?
     > )a
     >
     >
     > Thx
     >
     >
     >
     >
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