Adding FOREIGN KEY Constraint in column

Question

How can i add FOREIGN KEY constraint in the referrer_id(same as profile id) column? Since the column name contains parentheses it is throwing error

ALTER table Referrals ADD Constraint fk_referrer_ID 
       FOREIGN KEY(referrer_id(same as profile id)) REFERENCES Profiles(profile_id)

ERROR: Incorrect syntax near 'referrer_id(same as profile id)'.

Answer 1

在下面的查询中使用，列名用方括号（[]）分隔：

ALTER table Referrals ADD Constraint fk_referrer_ID FOREIGN KEY([referrer_id(same as profile id)]) REFERENCES Profiles(profile_id) 

Answer 2

I believe referrer_id is your column name

ALTER table Referrals ADD Constraint fk_referrer_ID 
        FOREIGN KEY(referrer_id) REFERENCES Profiles(profile_id) 

You don't to specify that it is same as profile id in foreign key, REFERENCES Profiles(profile_id) conveys that message to compiler.

or if you really have a ugly column name( referrer_id(same as profile id) ) then you need to use square brackets to escape the special characters present in your column name

ALTER table Referrals ADD Constraint fk_referrer_ID 
         FOREIGN KEY([referrer_id(same as profile id)]) REFERENCES Profiles(profile_id)