Question

I am using Oracle Express Eddition 10g.

The DDL below throws a DB error on the line with “REFERENCES TABLE_A_PK”

“SQL Error: ORA-00942: table or view does not exist”

CREATE TABLE TABLE_A (
    COLUMN_A    NUMBER,
    COLUMN_B    NUMBER,
    COLUMN_C    NUMBER,
    COLUMN_D    NUMBER,
    CONSTRAINT TABLE_A_PK 
        PRIMARY KEY (COLUMN_A, COLUMN_B)
)

CREATE TABLE TABLE_B (
    COLUMN_A    NUMBER,
    COLUMN_B    NUMBER,
    COLUMN_Y    NUMBER,
    COLUMN_Z    NUMBER,

    CONSTRAINT TABLE_A_FK 
        FOREIGN KEY (COLUMN_A, COLUMN_B)
        REFERENCES TABLE_A_PK
)

Can I use a named constrain as a foreign key reference? If so how?

Answer 1

You don’t specify the name of the key you are referencing, you specify the columns so, no, you can’t reference the name of the constraint. You need to specify something like

CREATE TABLE TABLE_B (
    COLUMN_A    NUMBER,
    COLUMN_B    NUMBER,
    COLUMN_Y    NUMBER,
    COLUMN_Z    NUMBER,

    CONSTRAINT TABLE_A_FK 
        FOREIGN KEY (COLUMN_A, COLUMN_B)
        REFERENCES TABLE_A( COLUMN_A, COLUMN_B )
)