In the where clause:
("INVCDETH_NF"."Z_INV_DATE">={d '2013-12-08'} AND "INVCDETH_NF"."Z_INV_DATE"<={d '2013-12-26'})
do you want to compare Z_INV_DATE to the hardcoded values '2013-12-08' and '2013-12-26'?
In the where clause:
("INVCDETH_NF"."Z_INV_DATE">={d '2013-12-08'} AND "INVCDETH_NF"."Z_INV_DATE"<={d '2013-12-26'})
do you want to compare Z_INV_DATE to the hardcoded values '2013-12-08' and '2013-12-26'?