Crreate table with foreign keys - sql

I m trying to create a table in sql, but it gives me an error when I add the foreign key from the table COURSE. With the other foreign keys it; Can anybody tell me why.
Here is my query
CREATE TABLE ENROLL (
Stu_ID NUMBER NOT NULL,
Prog_ID VARCHAR2(20) NOT NULL,
Crs_ID NUMBER NOT NULL,
Crs_Sec_ID VARCHAR2(20) NOT NULL,
Enroll_Outcome CHAR(1) NOT NULL,
PRIMARY KEY(Stu_ID),
FOREIGN KEY(Stu_ID) REFERENCES STUDENT(Stu_ID),
FOREIGN KEY(Prog_ID) REFERENCES PROGRAMS(Prog_ID),
FOREIGN KEY (Crs_Sec_ID) REFERENCES COURSE_SECTION (Crs_Sec_ID),
FOREIGN KEY(Crs_ID) REFERENCES COURSE(Crs_ID));
and here's the output
Error starting at line : 126 in command -
CREATE TABLE ENROLL (
Stu_ID NUMBER NOT NULL,
Prog_ID VARCHAR2(20) NOT NULL,
Crs_ID NUMBER NOT NULL,
Crs_Sec_ID VARCHAR2(20) NOT NULL,
Enroll_Outcome CHAR(1) NOT NULL,
PRIMARY KEY(Stu_ID),
FOREIGN KEY(Stu_ID) REFERENCES STUDENT(Stu_ID),
FOREIGN KEY(Prog_ID) REFERENCES PROGRAMS(Prog_ID),
FOREIGN KEY (Crs_Sec_ID) REFERENCES COURSE_SECTION (Crs_Sec_ID),
FOREIGN KEY(Crs_ID) REFERENCES COURSE(Crs_ID))
Error report -
SQL Error: ORA-02267: column type incompatible with referenced column type
02267. 00000 - "column type incompatible with referenced column type"
*Cause: The datatype of the referencing column is incompatible with the
AGAIN, it runs well with all of the other foreign key without the Crs_ID.

Basically what is says is Couse ID in Enroll table and Couse ID in Couse table are incompatible. Both columns should have the same types and properties (not null) in order to make a foreign key relationship.
Things to check:
Are they both have the same Column type (should be Number)?
Both are not support null?

Related

I'm trying to create a primary key from 2 columns, but it doesn't work well

I'm learning Oracle by myself.
Here's my code:
create table Schedule
(
Schedule_SN number(10) primary key,
ScreeningDate date not null,
Price number(6) not null
);
create table Seat
(
Schedule_SN number(10) REFERENCES Schedule(Schedule_SN),
Seat_SN varchar2(4) not null
);
create table Reservation
(
Reservation_SN number(15) primary key,
DCtype number(2) not null,
DCamount number(7),
PaymentMethod number(1) not null,
TotalPrice number(7) not null,
ReservationDate date not null
);
create table Reservation_details ** I need help here **
(
Reservation_SN number(15) REFERENCES Reservation(Reservation_SN),
Schedule_SN number(10) REFERENCES Schedule(Schedule_SN),
Seat_SN varchar2(10) REFERENCES Seat(Seat_SN),
CONSTRAINT Reservation_detailesPK primary key (Reservation_SN, Schedule_SN)
);
Error messages:
Errors - 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
How can I make my 2 columns (Reservation_SN, Schedule_SN) into a primary key?
The problem is with seat_sn. You want child column in reservation_details to reference parent column in seat, but the parent column is not a primary or unique key. Actually, seat has no primary key; just make seat_sn the primay key of this table (if this fits your use case), and the rest should run fine:
create table seat (
schedule_sn nmber(10) references schedule(schedule_sn),
seat_sn varchar3(4) primary key
)
Demo on DB Fiddle

ERROR: violates foreign key constraint, key is not present in parent table (but it is??)

I know this question has been asked many times, but none of the answers have solved my issue.
I am creating a database for a uni assignment, using PostgreSQL through pgadmin 4, and I have a table named "staff" populated with staff members with a primary key of "staffid". I then have another table named "client_international", which includes a foreign key of "staffid" which relates to the staff tables primary key.
When trying to insert into the client table, I am getting the following error:
ERROR: insert or update on table "client_international" violates foreign key constraint "intclient_staff_fkey"
DETAIL: Key (staffid)=(100000024) is not present in table "staff".
SQL state: 23503
I am certain that that '100000024' key is in the staff table.. yet I still get the error. Any suggestions? Below I will paste the code I used to create the staff and client tables, in case anyone notices an error in them.
Staff table:
CREATE SEQUENCE staff_seq
start 100000000
increment 1;
CREATE TABLE staff
(
staffid integer default nextval('staff_seq'),
firstname varchar(20) NOT NULL,
lastname varchar(20) NOT NULL,
"position" varchar(20) NOT NULL,
mobile varchar(20) NOT NULL,
email varchar(100) NOT NULL,
"location" integer NOT NULL,
CONSTRAINT staff_pkey PRIMARY KEY (staffid)
);
Client table:
CREATE SEQUENCE client_seq
start 200000000
increment 1;
CREATE TABLE client
(
clientid integer default nextval('client_seq'),
company varchar(100) NOT NULL,
sector varchar(100) NOT NULL,
pointofcontact varchar(20) NOT NULL,
mobile varchar(20) NOT NULL,
email varchar(100) NOT NULL,
approvalstatus boolean default (false),
"location" integer NOT NULL,
staffid integer NOT NULL,
CONSTRAINT client_pkey PRIMARY KEY (clientid)
);
CREATE TABLE client_international
(
CONSTRAINT client_international_pkey PRIMARY KEY (clientid)
) INHERITS ("client");
ALTER TABLE client
ADD CONSTRAINT client_location_fkey FOREIGN KEY ("location") REFERENCES "location" (locationid),
ADD CONSTRAINT client_staff_fkey FOREIGN KEY (staffid) REFERENCES staff (staffid);
ALTER TABLE client_international
ADD CONSTRAINT intclient_location_fkey FOREIGN KEY ("location") REFERENCES "location" (locationid),
ADD CONSTRAINT intclient_staff_fkey FOREIGN KEY (staffid) REFERENCES staff (staffid);
I get the error when running the following statements:
INSERT INTO client_international(company, sector, pointofcontact, mobile, email, approvalstatus, "location", staffid)
VALUES ('Moores Dogs', 'Border Patrol', 'Carol Moore', '07911 653453', 'jenkinsj#k9solutions.co.uk', 'false', '500000001', '100000024');
Here's a screenshot of the entry in the staff table, showing that it's definitely in there:
Foreign keys aren't "inherited".
Quote from the manual
A serious limitation of the inheritance feature is that [...] foreign key constraints only apply to single tables, not to their inheritance children. This is true on both the referencing and referenced sides of a foreign key constraint.
(emphasis mine)
So what you are trying to do, simply isn't supported.

Oracle SQL Database error: "no matching unique or primary key for this column-list"

I'm trying to set up a database in Oracle sql developer, I've got these 3 tables.
I need the table "GuyAddress" to have 3 primary keys, which are all foreign keys as well. This is where I'm running into an error which I can't get my head around.
CREATE TABLE Guy
(
id NUMBER(10) PRIMARY KEY,
name VARCHAR(50)
);
CREATE TABLE Address
(
zipcode VARCHAR(6),
"number" NUMBER(10),
CONSTRAINT PK_Address PRIMARY KEY(zipcode, "number")
);
CREATE TABLE GuyAddress
(
Guy_id NUMBER(10),
Address_zipcode VARCHAR(6),
Address_number NUMBER(10),
CONSTRAINT FK_GuyAddress_Guy_id FOREIGN KEY(Guy_id) REFERENCES Guy(id),
CONSTRAINT FK_GuyAddress_Address_zipcode FOREIGN KEY(Address_zipcode) REFERENCES Address(zipcode),
CONSTRAINT FK_GuyAddress_Address_number FOREIGN KEY(Address_number) REFERENCES Address("number"),
CONSTRAINT PK_GuyAddress PRIMARY KEY(Guy_id, Address_zipcode, Address_number)
);
This is the error, hopefully someone can spot the mistake I made because I can't...
Error starting at line : 18 in command -
CREATE TABLE "GuyAddress"
(
Guy_id NUMBER(10),
Address_zipcode VARCHAR(6),
Address_number NUMBER(10),
CONSTRAINT FK_GuyAddress_Guy_id FOREIGN KEY(Guy_id) REFERENCES Guy(id),
CONSTRAINT FK_GuyAddress_Address_zipcode FOREIGN KEY(Address_zipcode) REFERENCES Address(zipcode),
CONSTRAINT FK_GuyAddress_Address_number FOREIGN KEY(Address_number) REFERENCES Address("number"),
CONSTRAINT PK_GuyAddress PRIMARY KEY(Guy_id, Address_zipcode, Address_number)
)
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
Thanks!
You don't need separate foreign keys for each column in the referenced table's primary key - you can have multiple columns in a foreign key, e.g.:
CREATE TABLE Guy
(
id NUMBER(10) PRIMARY KEY,
name VARCHAR(50)
);
CREATE TABLE Address
(
zipcode VARCHAR(6),
address_number NUMBER(10),
CONSTRAINT PK_Address PRIMARY KEY(zipcode, address_number)
);
CREATE TABLE GuyAddress
(
Guy_id NUMBER(10),
Address_zipcode VARCHAR(6),
Address_number NUMBER(10),
CONSTRAINT FK_GuyAddress_Guy_id FOREIGN KEY(Guy_id) REFERENCES Guy(id),
CONSTRAINT FK_GuyAddress_Address FOREIGN KEY(Address_zipcode, Address_number) REFERENCES Address(zipcode,address_number),
CONSTRAINT PK_GuyAddress PRIMARY KEY(Guy_id, Address_zipcode, Address_number)
);
Note that I've updated your address.number column to be address.address_number, as it's not recommended that you use a column based on a keyword. Using doublequotes to get around this (and also enforce case sensitivity) is not recommended either; you'll have to remember to use them every time you reference that column!
As an aside, I assume that your address table has other columns? Because as things stand, the address table is pointless and could be skipped!

Error creating database with multiple primary key columns and referencing foreign key

I've been having an issue when creating a database. Each table has a primary key with many foreign keys used also. The issue I have is that I keep getting the error
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
I don't know what is causing this and is flagging the PROJECT_RECORDS table as the issue. I have used the same method in the PROJECT_TABLES table.
SQL/Oracle
CREATE TABLE PROJECT_DB
(DB_ID number (3) NOT NULL primary key,
DB_NAME varchar2 (25) NOT NULL,
DB_DESCRIPTION varchar2 (75) NOT NULL,
DB_DATE date NOT NULL);
CREATE TABLE PROJECT_DATATYPE
(DATATYPE_NAME varchar2 (20) NOT NULL PRIMARY KEY,
DATATYPE_DATATYPE varchar2(50) NOT NULL);
CREATE TABLE PROJECT_TABLES (
PROJECT_ID number(3) not null references PROJECT_DB(DB_ID) on delete cascade,
PROJECT_FIELDNAME varchar2(25) not null,
PROJECT_DATATYPE varchar2(50) not null references PROJECT_DATATYPE(DATATYPE_NAME),
PROJECT_LENGTH number(3),
PROJECT_REQUIRED varchar2(8),
PROJECT_LISTCOLUMNID number (3) not null,
primary key(PROJECT_ID, PROJECT_LISTCOLUMNID));
CREATE TABLE PROJECT_RECORDS (
RECORDS_ROWID number(3) not null,
RECORDS_LISTCOLUMNID number (3) not null references PROJECT_TABLES(PROJECT_LISTCOLUMNID)on delete cascade,
RECORDS_LISTID number (3) not null,
RECORDS_RECORDVALUE varchar2 (25),
primary key(RECORDS_ROWID, RECORDS_LISTCOLUMNID));
commit;
The reasoning for adding multiple primary keys to the PROJECT_TABLES table is that the listcolumnid isn't unique.
If listcolumnid is not unique, you cannot put a foreign key constraint on it. A foreign key always refrences exatcly one parent row. So you probably should use both columns in your foreign key (assuming there is really a 1:n relation):
CREATE TABLE PROJECT_RECORDS (
RECORDS_ROWID number(3) not null,
RECORDS_ID number(3) not null,
RECORDS_LISTCOLUMNID number (3) not null,
RECORDS_LISTID number (3) not null,
RECORDS_RECORDVALUE varchar2 (25),
primary key(RECORDS_ROWID, RECORDS_LISTCOLUMNID),
foreign key fk_project_projectrecords (RECORDS_ID, RECORDS_LISTCOLUMNID) references PROJECT_TABLES(PROJECT_ID, PROJECT_LISTCOLUMNID)on delete cascade,
);
(The example is using your prefix naming convention, I would change RECORDS_ID to PROJECT_ID, same for RECORDS_LISTCOLUMNID)
The problem is with your syntax. You don't do this:
, fieldname datatype references (something)
You do this:
, primary key(somefield)
, foreign key (somefield) references sometable(somefield)

Invalid FK and PK reference

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.