where not exists

[ttal7878]

HI,

In the example attached, I try to use the where not exists

Because I do not have a unique field in my table,  when I load the model it causes me to lose data,

only one row with ID = D is added to the main table

How can I load Table A and add the data from Table B but only the ID's that do not exist in Table A?

[ttal7878]