I have the following data in gfsh DB:
Region A:
column_X | column_Y
--------------------------
A=a1,B=b1,C=c1 | D=d1
A=a2,B=b2,C=c2 | D=d2
Region B:
column_M | column_N
----------------------------
A=a1 | H=h1
A=a3 | H=h3
I want to query: for all the column_M from region_B, if exist in Region_A, get the result of column_Y
How I can design the query? Thanks.