How to get all columns in final table after joining 2 tables-CodePudding

I have 2 tables T1 and T2. I need to join based on gt and gcd. Both tables are having a column named gcd. How to modify the below query to get both gcd columns from 2 tables in the final table.

select T1.*
, NVL(T2.gcd,'U')::VARCHAR(1) AS gcd
FROM T1
LEFT JOIN TABLE2 T2 ON T2.gt=  T1.gcd

CodePudding user response：

The columns need to have different names. You either rename the second "gcd", which you are getting from T2, or rename both to new names.

select T1.*
, NVL(T2.gcd,'U')::VARCHAR(1) AS gcd_t2
FROM T1
LEFT JOIN TABLE2 T2 ON T2.gt=  T1.gcd