Re: PK/Fk question

The opposite end of a 'foreign key' has to be a 'unique key' or 'primary key'. You have only two 'nominally correct' options -

1. declare a unique key on table1.col1 or
2. Create a table where the unique values of table1.col1 are held, and declare a primary key on it - them make table1 and table2 reference it.

Your question does, of course, suggest that there may be a flaw in your physical database structure.

Jonathan Lewis

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-----Original Message-----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Date: 27 August 2001 17:42

|Hi DBAs,
|
|Table1 PK is on columns col1,col2,col3
|I want to create a FK on table2 to table1 for col1.
|
|What is the alternative to
|ALTER TABLE table2
|ADD CONSTRAINT fk_table2
|FOREIGN KEY (col1) REFERENCES table1(col1);
|
|I always get ORA-2270: No matching unique or primary key for this
|column-list.
|Every value for table2.col1 is in the table table1.col1. I want to
enforce
|this at the database server level.
|
|Thanks
|Rick

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Author: Jonathan Lewis
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