Question question about relation and expression in dataset

[pooya1072]

hi
i have a dataset with10 datatable . can i specify an expression for a datatable that refer to columns of all other 9 tables.
i know that first i must define relation between tables.but i dont know which model of relation.
please help me about it.

 

[jmcilhinney]

Are you saying that you don't know how to create the DataRelation or the Expression?