inner join do not duplicate the column code example
Example: join creating duplicate columns sqllite
select
t1.cust_id, t1.col1, t1.col2,
t2.col1_table2, t2.col2_table2,
t3.col1_table3, t3.col2_table3
from
table1 t1
inner join
table2 t2 on t1.cust_id = t2.cust_id
join table3 t3 on t1.cust_id = t3.cust_id