Select a table column from the chart value

[#1]

I want to get a colulm from the following condition.

Chart                                                                                         CODE_DETAIL (Island Table)

code1   sum(corresponding code1 value)                                      code     code_name

1          100                                                                                1         A

2          200                                                                                2         B

3          300                                                                                3         C

The Chart that I want

code1   sum(corresponding code1 value)  code_name

1          100                                            A
2          200                                            B

3          300                                            C

I had to design the CODE_DETAIL as an island table for some reasons.

I tried the expression code_name as

  Only({<code = p(code1)>} code_name)

The result was different as I  expected cause the count of the expression is more than 1.

Isn't there any way to solve the problem?