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
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
Check the tables you are referencing in your foreign keys. Those columns must be the primary key or otherwise unique on the foreign table.
Related
I am having a problem connecting my Sample_Measure_FK in the Sample table to the Measurement Table.
There sections of code are:
create table Sample
(
Site_ID varchar2(5) not null,
Recorded_On timestamp not null,
Scientist_Num varchar2(7) not null,
Comments varchar2(4000), -- or CLOB
constraint Sample_PK primary key (Site_ID, Recorded_On),
constraint Sample_Site_FK foreign key (Site_ID) references Site,
constraint Sample_Scientist_FK foreign key (Scientist_Num) references Scientist(Scientist_Num),
-- the following is the problem:
constraint Sample_Measure_FK foreign key (Recorded_On) references Measurement(Recorded_On)
);
create table Measurement
(
Site_ID varchar2(5) not null,
Recorded_On timestamp not null,
Name varchar2(50),
Value numeric(10,8),
Outlier_Indicator varchar2(50),
constraint Measurement_PK primary key(Site_ID, Recorded_On),
);
The error message I receive is:
Error starting at line : 65 in command -
create table Sample
(
Site_ID varchar2(5) not null,
Recorded_On timestamp not null,
Scientist_Num varchar2(7) not null,
Comments varchar2(4000), -- or CLOB
constraint Sample_PK primary key (Site_ID, Recorded_On),
constraint Sample_Site_FK foreign key (Site_ID) references Site,
constraint Sample_Scientist_FK foreign key (Scientist_Num) references Scientist(Scientist_Num),
constraint Sample_Measure_FK foreign key (Recorded_On) references Measurement(Recorded_On)
)
Error report -
SQL Error: ORA-02270: no matching unique or primary key for this column-list
02270. 00000 - "no matching unique or primary key for this column-list"
*Cause: A REFERENCES clause in a CREATE/ALTER TABLE statement
gives a column-list for which there is no matching unique or primary
key constraint in the referenced table.
*Action: Find the correct column names using the ALL_CONS_COLUMNS
catalog view
The Other foreign keys work, but the one in bold does not.
Perhaps it is the naming, but I would expect a single sample to have multiple measurements, suggesting that the foreign key relationship is on the wrong table:
create table Sample (
Site_ID varchar2(5) not null,
Recorded_On timestamp not null,
Scientist_Num varchar2(7) not null,
Comments varchar2(4000), -- or CLOB
constraint Sample_PK primary key (Site_ID, Recorded_On)
constraint Sample_Site_FK foreign key (Site_ID) references Site,
constraint Sample_Scientist_FK foreign key (Scientist_Num) references Scientist(Scientist_Num)
);
create table Measurement (
Site_ID varchar2(5) not null,
Recorded_On timestamp not null,
Name varchar2(50),
Value numeric(10, 8),
Outlier_Indicator varchar2(50),
constraint Measurement_Sample_FK foreign key (Site_ID, Recorded_On) references Sample(Site_ID, Recorded_On),
constraint Measurement_PK primary key (Site_ID, Recorded_On, Name)
);
This does work.
The Measurement table needs to be created before the Sample table
The foreign key is validated, so the referenced table must already exist.
A foreign key needs to point to a primary key of another table
constraint Sample_Measure_FK foreign key (Recorded_On) references Measurement(Recorded_On)
Well, Recorded_on is not the primary key on Measurement. Alternatively it could be a unique constraint also, but it's not either.
You usually point foreign keys to primary keys of other tables.
I'm getting an error from oracle that says "number of referencing columns must match referenced columns."
I want my column recorded_on in the table measurement to reference recorded_on in the table called sample
The column Recorded on in the Sample table must be part of a composite key together with Scientist_Num
The error is coming from
FOREIGN KEY (Recorded_On) REFERENCES Sample(Scientist, Recorded_On, Site_ID)
CREATE TABLE Sample (
Scientist_Num varchar2(5) not null,
Recorded_On date not null,
Site_ID varchar2(4) not null,
Comments clob,
Primary key (Scientist_Num, Recorded_On),
FOREIGN KEY (Scientist_Num) REFERENCES Scientist(Scientist_Num),
FOREIGN KEY (Site_ID) REFERENCES Site(Site_ID)
);
CREATE TABLE Measurement (
Site_ID varchar2(4) not null,
Recorded_On date not null,
Name varchar2(10) not null,
Value varchar2(10),
Outlier_Indicator varchar2(10),
Primary key (Site_ID, Recorded_On, Name),
FOREIGN KEY (Site_ID) REFERENCES Sample(Site_ID),
FOREIGN KEY (Recorded_On) REFERENCES Sample(Scientist, Recorded_On, Site_ID)
);
The Scientist_Num and Recorded_On columns must be in a composite key together.
The answer to my problem and an explanation of what went wrong would be greatly appreciated.
You can create virtual column in sample table:
Recorded_virtual varchar2(5) [GENERATED ALWAYS] AS
(Scientist||Recorded_On||Site_ID) [VIRTUAL]
And create reference to this column:
CONSTRAINT fk_column
FOREIGN KEY (Recorded_On)
REFERENCES Sample(Recorded_virtual )
Foreign key references need to match the primary keys in number and type. So I think you intend:
CREATE TABLE Measurement (
Site_ID varchar2(4) not null,
Scientist_Num varchar2(5) not null,
----^ added for foreign key reference
Recorded_On date not null,
Name varchar2(10) not null,
Value varchar2(10),
Outlier_Indicator varchar2(10),
Primary key (Site_ID, Recorded_On, Name),
FOREIGN KEY (Site_ID) REFERENCES Site(Site_ID),
-------------------------------------^ Presumably you intend the site table
FOREIGN KEY (Scientist_Num, Recorded_On) REFERENCES
Sample(Scientist_Num, Recorded_On)
-----------------^ two columns, both need to already be defined
);
I suspect there are other issues with your data model, but this should fix the syntax error. If you want further help, then ask another question.
I'm in the process of building a database and have already successfully created 2 primary key tables however when I try to bring them in as 2 foreign keys to another table I am running into a
"CLIENTID" invalid identifier
Unsure how to resolve as not the best at this.
CREATE TABLE Booking(
BookingID number(10) NOT NULL,
CONSTRAINT Client_FK FOREIGN KEY (ClientID) REFERENCES client (ClientID),
CONSTRAINT Course_FK FOREIGN KEY (CourseID) REFERENCES course (CourseID),
CONSTRAINT Booking_PK PRIMARY KEY (ClientID, CourseID)
);
You are missing the columns on which your primary key and foreign keys are created; you need something like the following, to be edited with the right type for your columns:
CREATE TABLE Booking(
BookingID number(10) NOT NULL,
ClientId number, -- missing
CourseID number, -- missing
CONSTRAINT Client_FK FOREIGN KEY (ClientID) REFERENCES client (ClientID),
CONSTRAINT Course_FK FOREIGN KEY (CourseID) REFERENCES course (CourseID),
CONSTRAINT Booking_PK PRIMARY KEY (ClientID, CourseID)
)
I am pretty new to SQL and I have a problem. I want to make a recursive relationship (a table that relates to itself), but I get an error when I try to execute my code. It's working fine without the Coordinator_Office_ID foreign key.
The error is:
The number of columns in the foreign-key referencing list is not equal
to the number of columns in the referenced list.
Create table Logistican (
Office_ID Number(10) Constraint nb_office Not NULL,
Worker_ID Number(15) Constraint lg_worker not null,
Name_logistican Varchar(20),
Room Varchar(10) constraint log_room UNIQUE,
Coordinator_Office_ID Integer,
Primary key (Office_ID, Worker_ID),
Constraint work_id Foreign key (Worker_ID) References worker(worker_ID) on delete cascade,
Constraint lg_cord_id Foreign key (Coordinator_Office_ID) References Logistican(Office_ID)
);
Yes, that's cause you have defined composite primary key like Primary key (Office_ID, Worker_ID) and thus your FK should include both of them else it will result in PFD (partial functional dependency)
Add the constraint with alter table:
Create table Logistican (
Office_ID Number(10) Constraint nb_office Not NULL,
Worker_ID Number(15) Constraint lg_worker not null,
Name_logistican Varchar(20),
Room Varchar(10) constraint log_room UNIQUE,
Coordinator_Office_ID Integer,
Primary key (Office_ID, Worker_ID),
Constraint work_id Foreign key (Worker_ID) References worker(worker_ID) on delete cascade
);
alter table Logistican
add Constraint lg_cord_id
Foreign key (Coordinator_Office_ID, Worker_Id) References Logistican(Office_ID, Worker_Id);
The relationship needs all elements of the primary key to be valid. I'm not sure if it needs to be a separate statement in Oracle.
I have 1st table:
CREATE TABLE HEAD (
Code int,
Name varchar(99),
HType char(1),
HDate date,
OpBal number(10),
CONSTRAINT pk_head PRIMARY KEY (Code, Name));
and 2nd table:
CREATE TABLE SUBHEAD (
HCode int,
SubCode int,
Name varchar(99),
SDate date,
OpBal number(10),
CONSTRAINT fk_subhead FOREIGN KEY (HCode) REFERENCES HEAD(Code),
CONSTRAINT pk_subhead PRIMARY KEY (Hcode, SubCode));
Now when I run the script, I get:
CONSTRAINT fk_subhead FOREIGN KEY (HCode) REFERENCES HEAD(Code),
ERROR at line 7:
ORA-02256: number of referencing columns must match referenced columns
I have been looking around trying to figure out what's wrong and I think it has something to do with parent table constraint but I am totally stumped on how to fix this.
Your problem is that your foreign key is not referencing the entire primary key from HEAD.
So you either need to change the foreign key (to include name in there) or change the primary key of HEAD to exclude name there.
So either change
CONSTRAINT pk_head PRIMARY KEY (Code, Name));
to
CONSTRAINT pk_head PRIMARY KEY (Code));
or change
CONSTRAINT fk_subhead FOREIGN KEY (HCode) REFERENCES HEAD(Code)
to
CONSTRAINT fk_subhead FOREIGN KEY (HCode, Name) REFERENCES HEAD(Code, Name)