Advanced ddlRelateEx() API Functionality

There are several advanced features of the ddlRelateEx() API that are used for processing more complex JOINs. <cx-1> [+ <cx-2> [+ ...]] [PRESENT BY <field1> <field2> ... [<value-clause>] [<calc-clause>] [<post-calc-clause>] Where: cx-1, cx-2 ... represent the names of collections that contain the index data;     Each cx JOIN is performed separately; then the results are combined into cx-1 with duplicates removed An alternative PRESENT BY WITH COUNT Clause performs the additional function of creating in internal array that contains the counts for each unique instance of the PRESENT BY Clause. The columns specified in the PRESENT BY WITH COUNT Clause must be included in the VALUE Clause. The PRESENT BY WITH COUNT Clause can be followed by a PRESENT BY Clause to specify columns that are not included in the PRESENT BY WITH COUNT Clause. These counts are available in Calc Object with the _pbcount() function.