In tmap, when one wants to join on fields between the main and the lookup table, if you drag several records at once from the top of the left hand panel to the bottom (to create a connection to join on), the default is 'append mode-all source entries to a single one target expression' (see screenshot attached). The result is that all the selected fiels end up after each other in one line.
I would like to switch this off so that when I drag fields, they all end up on separate lines. This would be very useful in case of many fields that you want to join on:
but what in case if:
- columns for join in parent table - 1,3,4
- in child - 2,9,15
I think -it to ambiguous for guess proper columns for join, they often have different names
Thanks for feedback.
OK, probably most often you will have different columns to join on but I happen to have two tables with many fields (>200) that are the same. As I can not just drag them, I need to enter the joins in the expression editor. However when I use the expression editor, at some point you can not click in the box anymore to enter the expression (as for every join a visual line is drawn). I am looking for a workaround and dragging them all at once would be the easiest one.
workaround it is 2 steps:
- request for tMap only columns used for JOIN AND primary keys, store 2 columns result - PK1, PK2 (and more if need) ... NULL all as usual
- use this result for request again from 2 database (possible to save requests into local files for make it faster) - and JOIN by PK1, PK2