Question

Unable to create table as oracle shows ‘ no matching unique or primary key for this column-list’ when I did label the primary key reference for the required table.

First table created successfully:

CREATE TABLE TEST
  (
    TESTno VARCHAR2(6) NOT NULL,
    ExamNo VARCHAR2(6) NOT NULL,
    TEST_Date DATE NOT NULL,
    ACTUAL DATE,
    PREDICTED Date,
    CONSTRAINT TESTPKs PRIMARY KEY (TEST_Date, TESTno, ExamNo),
    CONSTRAINT TTESTNO_Fk FOREIGN KEY (TESTno) REFERENCES TESTPAPER (Flightno)
    CONSTRAINT TEXAMNo_FK FOREIGN KEY (ExamNo) REFERENCES Exam (ExamNo)
  );

Here’s the table i want to create and gives me error:

CREATE TABLE Assignment
  (
    TEST_Date DATE NOT NULL,
    ExamNo VARCHAR2(6) NOT NULL,
    TestNo VARCHAR2(6) NOT NULL,
    Type  VARCHAR2(20),
    Hours_Spent Decimal(4,2),
    CONSTRAINT ASSIGNPKS PRIMARY KEY (TEST_Date, TestNo , ExamNo),
    CONSTRAINT ASSIGNTESTDATE_FK FOREIGN KEY (TEST_Date) REFERENCES TEST(TEST_Date) ON
  DELETE CASCADE,
    CONSTRAINT ASSIGNTESTNO_FK FOREIGN KEY (TESTno) REFERENCES TESTPAPER (Flightno)
    CONSTRAINT TEXAMNo_FK FOREIGN KEY (ExamNo) REFERENCES Exam (ExamNo)
  );

May i know where’s the issue that it keeps giving me no matching unique primary keys? I already tried to recreate and labelled the ‘test_Date’ as my primary key. But oracle can’t seems to find.

Thanks

Answer 1

The PK you refer to is PRIMARY KEY (TEST_Date, TESTno, ExamNo) — hence the foreign key should be FOREIGN KEY (TEST_Date, TESTno, ExamNo) as well. The error you’re getting is due to your attempt to refer to a part of TEST‘s PK.

See also http://download.oracle.com/docs/cd/B10500_01/server.920/a96524/c22integ.htm