I'm in a bit of a mix right now, I have a Table called Avatars, which has a foreign key called Family. Now, in the family table, I have two Foreign Keys called Mother and Father - Now this is the confusing bit, in both the Mother and Father Tables, there is a Foreign key called Avatar_ID which is of course the Primary Key to the Avatars table. I'm not sure if that's even allowed in SQL PLUS.
Whenever I try and enter the tables 'Family, Mother or Father', I keep getting the error:ORA-02291: integrity constraint (SG304.FK_FATHER_ID) violated - parent key not found.
Is there any way around this? Or will I have to change my code completely? A sample of the code is below.
CREATE TABLE Avatars (
Avatar_ID VARCHAR(10) NOT NULL,
Avatar_Name VARCHAR(30),
AvA_DOB DATE,
Age VARCHAR(30),
Gender VARCHAR(30),
Strength_Indicated INT,
Hoard INT,
Avatar_Level VARCHAR(30),
Skill VARCHAR(30),
Original_Owner VARCHAR(30),
Family_ID VARCHAR(10) NOT NULL,
Species_ID VARCHAR(10) NOT NULL,
Inventory_ID VARCHAR(30) NOT NULL,
Weapon_ID VARCHAR(10),
Player_ID VARCHAR(10) NOT NULL,
PRIMARY KEY (Avatar_ID));
CREATE TABLE Family (
Family_ID VARCHAR(10) NOT NULL,
Mother_ID VARCHAR(10) NOT NULL,
Father_ID VARCHAR(10) NOT NULL,
primary key(Family_ID)
);
CREATE TABLE Mother (
Mother_ID VARCHAR(10) NOT NULL,
Avatar_ID VARCHAR(10) NOT NULL,
primary key(Mother_ID)
);
CREATE TABLE Father (
Father_ID VARCHAR(10) NOT NULL,
Avatar_ID VARCHAR(10) NOT NULL,
primary key(Father_ID)
);
ALTER TABLE Avatars
ADD CONSTRAINT fk_Family_ID
FOREIGN KEY (Family_ID)
REFERENCES Family(Family_ID);
ALTER TABLE Family
ADD CONSTRAINT fk_Mother_ID
FOREIGN KEY (Mother_ID)
REFERENCES Mother(Mother_ID);
ALTER TABLE Family
ADD CONSTRAINT fk_Father_ID
FOREIGN KEY (Father_ID)
REFERENCES Father(Father_ID);
ALTER TABLE Father
ADD CONSTRAINT fk_Avatar_ID
FOREIGN KEY (Avatar_ID)
REFERENCES Avatars(Avatar_ID);
ALTER TABLE Mother
ADD CONSTRAINT fk_Avatars_ID
FOREIGN KEY (Avatar_ID)
REFERENCES Avatars(Avatar_ID);
INSERT INTO Avatars (Avatar_ID,Avatar_Name,AvA_DOB,Age,Gender,Strength_Indicated,Hoard,Avatar_Level, Skill, Original_Owner, Family_ID,Species_ID,Inventory_ID,Player_ID) VALUES
('Ava01','Verda','20-JAN-2014','1 year 2 months','Female','100','20','Master','Leader',' - ',' - ','DRA1','MasterInventory','Player07');
Thanks in advance for any help given! (:
Foreign key refers to a record in parent table. In your INSERT statement you are inserting value ' - ' into a column parent_id. In this error message oracle informs you that there is no record with value ' - ' in a column family_id of a table family. As I can understand, you are trying to use ' - ' as 'absence of value'. There is special value for that - NULL. So you need to write your statement as:
INSERT INTO Avatars (Avatar_ID, Avatar_Name, AvA_DOB,
Age, Gender, Strength_Indicated, Hoard, Avatar_Level, Skill,
Original_Owner, Family_ID, Species_ID, Inventory_ID, Player_ID)
VALUES ('Ava01', 'Verda', '20-JAN-2014', '1 year 2 months' ,'Female',
'100', '20', 'Master', 'Leader', NULL, NULL, 'DRA1',
'MasterInventory', 'Player07');
Also I can recommend some changes to your schema. First of all, use number data type for primary keys - it allows you to use sequences to generate unique values. Also, I don't know details of the problem, but "family relations" in your tables look a bit complicated. You can describe it in a single table:
create table family_tree (
person_id number primary key,
father_id number,
mother_id number,
sex char(1),
name varchar2(50),
family_name varchar2(50));
add constraint fk_mother_id foreign key (mother_id)
references family_tree (person_id);
add constraint fk_father_id foreign key (father_id)
references family_tree (person_id);
Related
I have this table:
CREATE TABLE cars_info.cars
(
id SERIAL,
owner_id INTEGER,
brand VARCHAR(50) NOT NULL,
model VARCHAR(50) NOT NULL,
color VARCHAR(50) NOT NULL,
register_number VARCHAR(50) NOT NULL,
created DATE NOT NULL,
PRIMARY KEY(id, brand, model, color, register_number, created),
CONSTRAINT fk_owner_id
FOREIGN KEY(owner_id)
REFERENCES persons_info.persons(id)
);
But when I tried create another table like this:
CREATE TABLE cars_info.violations
(
id SERIAL PRIMARY KEY,
car_id INTEGER NOT NULL,
message VARCHAR(100) NOT NULL,
active BOOLEAN NOT NULL,
CONSTRAINT fk_car_id
FOREIGN KEY(car_id)
REFERENCES cars_info.cars(id)
);
I get an error about that
Target external table "cars" does not have a unique constraint corresponding to the given keys
How can I fix that? I'm a beginner in SQL and don't know how to go about googling that
Your primary key definition for cars
PRIMARY KEY(id, brand, model, color, register_number, created)
makes no sense: The id column, being serial, is itself unique and it alone should be the primary key.
Delete your primary key definition and change the id column definition to:
id serial not null primary key
Unrelated, but best practice is to name table in the singular; name your tables car and violation rather than cars and violations
What I am trying to do ?
I am trying to create two tables and at the same time i am trying to link them together using foreign and primary keys. However I successfully create my parent table ( Student with primary key ) but failed to create child table ( Attendence with foreign key ).
What is the problem ?
I get the following error while creating Attendence table:
ERROR at line 5: ORA-01748: only simple column names allowed here
My code:
Student table:
create table Student (
ST_ROLLNO NUMBER(6) constraint s_pk primary key,
ST_NAME VARCHAR(30) not null,
ST_ADDRESS varchar(35) not null
);
Attendence table:
create table Attendence (
ST_ROLLNO NUMBER(6),
ST_DATE VARCHAR(30) not null,
ST_PRESENT_ABSENT varchar(1) not null,
constraint f_pk Attendence.ST_ROLLNO foreign key references Student(ST_ROLLNO)
);
Your foreign key constraint syntax is wrong; it should be:
constraint f_pk foreign key (ST_ROLLNO) references Student(ST_ROLLNO)
You are preceding the FK column name with the table name, which is wrong in itself, but also have it in the wrong place.
create table Student (
ST_ROLLNO NUMBER(6) constraint s_pk primary key,
ST_NAME VARCHAR(30) not null,
ST_ADDRESS varchar(35) not null
);
Table STUDENT created.
create table Attendence (
ST_ROLLNO NUMBER(6),
ST_DATE VARCHAR(30) not null,
ST_PRESENT_ABSENT varchar(1) not null,
constraint f_pk foreign key (ST_ROLLNO) references Student(ST_ROLLNO)
);
Table ATTENDENCE created.
According to oracle documentation,
ORA ERR
ORA-01748 only simple column names allowed here
The following is the cause of this error:
This SQL statement does not allow a qualified column name, such as
username.table.column or table.column.
Action you can take to resolve this issue: Remove the qualifications
from the column and retry the operation.
In your case, you are trying to refer to the table name while defining a constraint -
Attendence.ST_ROLLNO - WRONG.
It must contain a simple name without the table name or schema name.
I'm new to SQL and there are a lot of things going on that I still don't seem to quite understand. I have the following table
CREATE TABLE Person
(
First_Name varchar(20) NOT NULL,
Name varchar(20) NOT NULL,
Address varchar(50) NOT NULL,
PRIMARY KEY (First_Name, Name, Address)
);
I know want to create another table that has the primary key from the table Person as foreign key and also as primary key:
CREATE TABLE Purchase
(
No_Installments int,
Rate int,
Person varchar(50) NOT NULL PRIMARY KEY,
CONSTRAINT PFK
FOREIGN KEY (Person) REFERENCES Person (First_Name, Name, Address)
);
For some reason this doesn't work and I get an error every time. I've already looked up the other threads here on stackoverflow, but they don't really seem to help me. What am I doing wrong?
If you have a compound PK made up from three columns, then any child table that wants to establish a foreign key relationship must ALSO have all those 3 columns and use all 3 columns to establish the FK relationship.
FK-PK relationship is an all or nothing proposal - you cannot reference only parts of a primary key - either you reference all columns - or you don't reference.
CREATE TABLE Purchase
(
No_Installments int,
Rate int,
Person varchar(50) NOT NULL PRIMARY KEY,
First_Name varchar(20) NOT NULL,
Name varchar(20) NOT NULL,
Address varchar(50) NOT NULL,
CONSTRAINT PFK
FOREIGN KEY (First_Name, Name, Address)
REFERENCES Person (First_Name, Name, Address)
);
Have an integer primary key, using identity, auto_increment, serial or whatever for your database:
CREATE TABLE Person (
PersonId int identity PRIMARY KEY
First_Name varchar(20) NOT NULL,
Name varchar(20) NOT NULL,
Address varchar(50) NOT NULL,
CONSTRAINT unq_person_3 UNIQUE (First_Name, Name, Address)
);
Then use the identity column for the reference:
CREATE TABLE Purchase (
PurchaseId int identity PRIMARY KEY,
No_Installments int,
Rate int,
PersonId int,
CONSTRAINT PFK
FOREIGN KEY (PersonId) REFERENCES Person (PersonId)
);
Notes:
You really don't want to have to deal with a composite primary key. Have you thought about what the joins will look like?
You don't want a primary key where the values are subject to change. What happens when someone changes his/her name? When someone moves?
Person should not be the primary key in Purchases. Are you only allowing someone to make one purchase?
As noted initially, how you generate such a column varies by database; identity happens to be the way that SQL Server does this.
You probably want to assign a unique ID to each person, not relying on their name to be unique or for an address to be required. That ID will be your Primary key and foreign key. Your purchase table should also have its own id for its primary key -- otherwise because primary keys must be unique, each person can only have one purchase.
CREATE TABLE Person (
id serial NOT NULL,
First_Name varchar(20) NOT NULL,
Name varchar(20) NOT NULL,
Address varchar(50) NOT NULL,
PRIMARY KEY (id));
CREATE TABLE Purchase (
id serial NOT NULL,
No_Installments int,
Rate int,
Person int NOT NULL,
FOREIGN KEY (Person) REFERENCES Person (id),
PRIMARY KEY (id));
I'm trying to insert data into my SQL Server 2014 build and I keep getting this error. I tried searching all over the internet and at my whits end, I sort of get what people were saying but still having difficulty understanding what's wrong with my particular code.
All tables are empty without data. I cannot add data once the foreign keys are set. I read that both tables must be populated for this to work but how does that happen when I can't add anything? If I add data before the foreign key, then I'm unable to add foreign keys. Please help!
When trying to insert data into Gym row using the INSERT INTO I get this error:
The INSERT statement conflicted with the FOREIGN KEY constraint "FK__Gym__staffNo". The conflict occurred in database "FitnessApp", table "dbo.Staff", column 'staffNo'.
This also happens when trying to add data into the Equipment or Staff tables as well.
See code here:
Schema:
CREATE TABLE Gym
(
gymNo int NOT NULL IDENTITY(1,1),
staffNo int NOT NULL,
streetAddress varchar(100) NOT NULL,
streetAddress2 varchar(100) NULL,
city varchar(50) NOT NULL,
state char(2) NOT NULL,
zip char(5) NOT NULL,
phone char(10) NOT NULL
) ON [fitnessPlusGroup1];
CREATE TABLE Staff
(
staffNo int NOT NULL IDENTITY(1,1),
gymNo int NOT NULL,
position varchar(50) NOT NULL,
firstName varchar(50) NOT NULL,
lastName varchar(50) NOT NULL,
streetAddress varchar(100) NOT NULL,
streetAddress2 varchar(100) NULL,
city varchar(50) NOT NULL,
state char(2) NOT NULL,
zip char(5) NOT NULL,
phone char(10) NOT NULL,
hireDate date NOT NULL
) ON [fitnessPlusGroup1];
CREATE TABLE Member
(
memberNo int NOT NULL IDENTITY(1,1),
gymNo int NOT NULL,
firstName varchar(30) NOT NULL,
lastName varchar(30) NOT NULL,
streetAddress varchar(100) NOT NULL,
streetAddress2 varchar(100) NULL,
city varchar(50) NOT NULL,
state char(2) NOT NULL,
zip char(5) NOT NULL,
phone char(10) NOT NULL,
memberSince date NOT NULL,
scheduleID int NULL
) ON [fitnessPlusGroup1];
CREATE TABLE Schedule
(
scheduleID int NOT NULL IDENTITY(1,1),
staffNo int NOT NULL,
trainDate date NOT NULL,
trainTime time(0) NOT NULL
) ON [fitnessPlusGroup1];
CREATE TABLE Equipment
(
equipNo int NOT NULL IDENTITY(1,1),
gymNo int NOT NULL,
staffNo int NOT NULL,
name varchar(50) NOT NULL,
quantity int NOT NULL
) ON [fitnessPlusGroup1];
Foreign key relationships setup:
ALTER TABLE Gym
ADD FOREIGN KEY (staffNo) REFERENCES Staff(staffNo);
ALTER TABLE Staff
ADD FOREIGN KEY (gymNo) REFERENCES Gym(gymNo);
ALTER TABLE Member
ADD FOREIGN KEY (gymNo) REFERENCES Gym(gymNo);
ALTER TABLE Member
ADD FOREIGN KEY (scheduleID) REFERENCES Schedule(scheduleID);
ALTER TABLE Schedule
ADD FOREIGN KEY (staffNo) REFERENCES Staff(staffNo);
ALTER TABLE Equipment
ADD FOREIGN KEY (gymNo) REFERENCES Gym(gymNo);
ALTER TABLE Equipment
ADD FOREIGN KEY (staffNo) REFERENCES Staff(staffNo);
The insert commands that give errors:
INSERT INTO Gym(staffNo, streetAddress, streetAddress2, city, state, zip, phone)
VALUES (1, '7300 W Greens Rd', NULL, 'Houston', 'TX', '77064', '2818946151');
Any help would be much appreciated sorry if this seems like a bit much and I hope I provided all the info I could..
I think the problem is in your table design. Take these two FKEY, as an exmpale:
ALTER TABLE Gym
ADD FOREIGN KEY (staffNo) REFERENCES Staff(staffNo);
ALTER TABLE Staff
ADD FOREIGN KEY (gymNo) REFERENCES Gym(gymNo);
You cannot add a record to Gym until you've added the supporting staffNo to Staff. But you cannot add a record to Staff until you've added the supporting gymNo to Gym. These keys prevent you populating either table, as both require records to be present in the other.
Why is this? Because an FKey is like a promise. It guarantees that the value in column x can always be found in table y. In order to fulfill this promise table y must be populated first. But when you have a circular reference, back to the original table, this can never be achieved.
Here is one possible solution. You could remove the staffNo from Gym and GymNo from Staff. Then add a new table StaffGym. This table would have two fields staffNo and gymNo. It would be populated after Staff and Gym, providing a bridge between the two. This is called a cross reference table, or sometimes xref for short.
You say:
All tables are empty without data.
So there is no staffNo with id = 1 in your Staff. You've got a foreign key constraint so you can only reference items that exist. So you first need to populate the lookup data in Staff before you can link to it with an ID.
Also, remove one of the constraint between Staff and Gym, you have this:
ALTER TABLE Gym
ADD FOREIGN KEY (staffNo)
REFERENCES Staff(staffNo);
ALTER TABLE Staff
ADD FOREIGN KEY (gymNo)
REFERENCES Gym(gymNo);
When you only need one of these. I'd say remove it from Gym, as a Gym could have many staff I'd assume, and also remove the StaffNo column from Gym. As this is preventing you from creating one without the other. Once you've removed that link, you should insert data in the correct order.
The order of the inserts is key. If you remove the column I suggested above, you should insert in the following order based on your constraints:
Gym
Staff (requires gym record)
Schedule (requires staff record)
Member (requires schedule record)
Equipment (requires gym and staff record)
I did look up for solutions for this problem but i still get the same error..
I'm trying to insert values into PART and MANUFACTURER tables. Initially, i inserted values into MANUFACTURER without knowing the fact i need to deal with the parent table i.e. PART. So, i did the PART then the MANUFACTURER but still not working :(.
These are the tables:
PART(PNum, PName, PUnitPrice, ComponentOf)
primary key (PNum)
foreign key (ComponentOf) references PART(PNum)
MANUFACTURER(MName, MAddress, MPhone)
primary key (MName)
candidate key (MPhone)
candidate key (MAddress)
PART-MANUFACTURED(MDate, PNum, MName, Quantity)
primary key (MName, PNum, MDate)
foreign key (PNum) references PART(PNum)
foreign key (MName) references MANUFACTURER(MName)
CUSTOMER(CNum, CName, CType)
primary key (CNum)
domain constraint ctype in ('INDIVIDUAL', 'INSTITUTION')
ORDERS(CNum, PNum, OrderDate, OrderQuantity)
primary key (CNum, PNum, OrderDate)
foreign key (CNum) references CUSTOMER(CNum)
foreign key (PNum) references PART(PNum)
Create statements:
CREATE TABLE PART(PNum VARCHAR(25) NOT NULL, PName VARCHAR(75) NOT NULL, PUnitPrice NUMBER(7,2) NOT NULL, ComponentOf VARCHAR(25), PRIMARY KEY(PNum), FOREIGN KEY(ComponentOf) REFERENCES PART(PNum));
Table created.
SQL> CREATE TABLE MANUFACTURER(MName VARCHAR(50) NOT NULL, MAddress VARCHAR(100) NOT NULL, MPhone VARCHAR(25) NOT NULL, PRIMARY KEY(MName), CONSTRAINT UK_MADDRESS Unique(MAddress), CONSTRAINT UK_MPHONE UNIQUE(MPhone));
Table created.
SQL> CREATE TABLE PARTMANUFACTURED(MDate DATE NOT NULL, PNum VARCHAR(25) NOT NULL, MName VARCHAR(50) NOT NULL, QUANTITY NUMBER(10) NOT NULL, PRIMARY KEY(MName, PNum, MDate), FOREIGN KEY(PNum) REFERENCES PART(PNum), FOREIGN KEY(MName) REFERENCES MANUFACTURER(MName));
Table created.
SQL> CREATE TABLE CUSTOMER(CNum VARCHAR(25) NOT NULL, CName VARCHAR(75) NOT NULL, CType VARCHAR(20) NOT NULL, PRIMARY KEY(CNum), CHECK(Ctype in('INDIVIDUAL','INSTITUTION')));
Table created.
SQL> CREATE TABLE ORDERS(CNum VARCHAR(25) NOT NULL, PNum VARCHAR(25) NOT NULL, OrderDate DATE NOT NULL, OrderQuantity NUMBER(7,2) NOT NULL, PRIMARY KEY(CNum, PNum, OrderDate), FOREIGN KEY(CNum) REFERENCES CUSTOMER(CNum), FOREIGN KEY(PNum) REFERENCES PART(PNum));
Isn't the PNum already the primary or parent key? and PART table is the parent table? since, other tables have the PNum as foreign key.. i really don't get it..
anyone knows and can help me with it, is greatly appreciated. thanks :)
The error with your insert statement INSERT INTO PART VALUES('S001', 'System-economy', 1100, 'Null') is that you are trying to insert a string 'NULL' rather than an actual NULL for the column ComponentOf in the PART table.
The problem with the string 'NULL' is that you have a FOREIGN KEY constraint on ComponentOf that references the column PNum, which means that all the values in the column ComponentOf must also be in PNum. However, there is no value 'NULL' in PNum so that's why it threw the error. An actual NULL works since it means that it is not referencing anything.
The value inserted for ComponentOf has to match an existing PNum in the PARTS table. Your key is their to ensure you don't have any "orphaned" components.
If you try to insert 'Null' (a string value as mentioned in the comments) then it can't find the "parent". However, null is allowed since it means that particular part is not a component of any other part, i.e. it doesn't have a "parent".