Missing columns in a dataset

[Sshasnk]

Hi So I have a dataset and this dataset have column which I have to merge but sometime 1 or 2 columns are missing and because of that canvas throws an error 

Example: 

Input 1: 

t1	t2	t3	t4
a	b	c	d
e	f	g	h

output 1:

t1	t2	t3	t4	Output
a	b	c	d	a b c d
e	f	g	h	e f g h

Now sometimes the column is missing

Input 2:

t1

a

b

Output1:

t1	Output
a	a
b	b

[Qiu]

@Sshasnk 
We can use a transpose tool to be more dynamic