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I am a beginner. I created a query on PostgreSQL. I want to make CONSTRAINT with string and integer. It was successfully running but when I insert the data, it gave me an error
CREATE TABLE customer
(
id_customer char(5) PRIMARY KEY NOT NULL,
CONSTRAINT cek_id_customer CHECK ((left(id_customer,2) in ('CU'))
and substring(id_customer,3) LIKE '%[0-9]%'),
nama_customer varchar(30) NOT NULL,
gender_customer varchar(15) NOT NULL,
CONSTRAINT cek_gender_customer CHECK(gender_customer = 'Male' OR gender_customer = 'Female')
);
INSERT INTO customer
VALUES ('CU001', 'Sayaa', 'Male')
The message
ERROR: new row for relation "customer" violates check constraint "cek_id_customer"
DETAIL: Failing row contains (CU001, Sayaa, Male).
SQL state: 23514
To enforce the matching pattern you want you can use a regular expression matching rule in the constraint, like id_customer ~ '^CU[0-9]*$'.
For example:
CREATE TABLE customer (
id_customer char(5) PRIMARY KEY NOT NULL,
CONSTRAINT cek_id_customer CHECK (id_customer ~ '^CU[0-9]*$'),
nama_customer varchar(30) NOT NULL,
gender_customer varchar(15) NOT NULL,
CONSTRAINT cek_gender_customer CHECK(
gender_customer = 'Male' OR
gender_customer = 'Female'
)
);
INSERT INTO customer (id_customer, nama_customer, gender_customer)
VALUES ('CU001', 'Sayaa', 'Male'); -- succeeds
INSERT INTO customer (id_customer, nama_customer, gender_customer)
VALUES ('CU1X', 'Sayaa', 'Male'); -- fails!
See running example at DB Fiddle.
I am new to PostgreSQL and how i can update the records while they are related with a foreign key definition.
I am getting an error and that would be great if you can guide me with any hints
Let's say we have two different tables like below :
CREATE TABLE IF NOT EXISTS student
(
id_num VARCHAR(40) NOT NULL REFERENCES registered(student_id),
first_name VARCHAR(32) NOT NULL,
last_name VARCHAR(32) NOT NULL,
birthdate DATE NOT NULL,
PRIMARY KEY(id_num)
);
CREATE TABLE IF NOT EXISTS registered
(
student_id VARCHAR(40) NOT NULL UNIQUE,
paid_tuition BOOL NOT NULL,
PRIMARY KEY(paid_tuition)
);
Based on my understating i need to fill the registered table and then try to insert values to the student table that their id match the student_id value in registered table.
But when I try it I get the following error?
Any idea or recommendation?
Message:"update or delete on table "registered" violates foreign key
constraint "student_id_num_id_fkey" on table "student"",
Detail:"Key (id_num)=(idNum-1) is still referenced from table
"student".", Hint:"", Position:0, InternalPosition:0,
InternalQuery:"", Where:"", SchemaName:"", TableName:"student",
ColumnName:"", DataTypeName:"",
ConstraintName:"student_id_num_id_fkey", File:"ri_triggers.c",
Line:2490, Routine:"ri_ReportViolation"}
seems like you are linking tables in opposite direction , to me it makes more sense that "registered" table has been linked to student table by fk studentid .
also in your "student" table definition you are saying that column "id" is primary key while no "id" column has been declared.
so here is what I mean:
CREATE TABLE IF NOT EXISTS student
(
id_num VARCHAR(40) NOT NULL REFERENCES registered(student_id),
first_name VARCHAR(32) NOT NULL,
last_name VARCHAR(32) NOT NULL,
birthdate DATE NOT NULL,
PRIMARY KEY(id_num)
);
CREATE TABLE IF NOT EXISTS registered
(
student_id VARCHAR(40) NOT NULL REFERENCES student(id_num)
paid_tuition BOOL NOT NULL,
PRIMARY KEY(id_num)
);
CREATE table Book
(
book_title varchar (100) not null ,
book_genre char(60) not null,
Date_of_publish date not null,
user_code char(7) not null ,
book_id char (7) primary key not null ,
constraint writer__id_fk foreign key (writer_id),
constraint publisher__id_fk foreign key (publisher_id)
);
I'm getting
[ORA-00905: missing keyword]
in publisher table
CREATE table publisher
(
publisher_id char (7) primary key not null,
publisher_name char(20) not null,
publisher_number char(10) not null,
publisher_email varchar2(60) not null,
publisher_address varchar2(60) not null,
);
I'm getting
[ORA-00904: : invalid identifier]
The following SQL creates a FOREIGN KEY on the "PersonID" column when the "Orders" table is created:
CREATE TABLE Orders (
OrderID int NOT NULL,
OrderNumber int NOT NULL,
PersonID int,
PRIMARY KEY (OrderID),
FOREIGN KEY (PersonID) REFERENCES Persons(PersonID)
);
Refer this link for more details
https://www.w3schools.com/sql/sql_foreignkey.asp
Hope this helps.
Welcome to the wonderful world of SQL! :-)
General remark:
Please tell us what kind of DBMS you're using. MySQL? SQL Server? Oracle? SQlite? Different systems use different kinds of syntaxes.
First statement:
The problem seems to be in the FOREIGN KEY-portion.
Usually, you'll state something like:
CONSTRAINT [constraint_name] FOREIGN KEY([column_in_this_table]) REFERENCES OTHER_TABLE([column_in_other_table])
edit (added):
The [column_in_this_table] has to exist in your DDL (CREATE TABLE-statement), like so:
CREATE TABLE Book ( book_title ... etc., publisher_id INT, CONSTRAINT FK_publ_id FOREIGN KEY(publisher_id) REFERENCES publisher(publisher_id));
Here, you'll have a 'original' column called 'publisher_id', in the 'publisher'-table. You refer to it from within the 'Book'-table, by first having a 'publisher_id' column in the 'Book'-table (which should have the same DDL as the original column by the way). Next, you'll add a FOREIGN KEY to the 'Book'-table, that is imposed on the Book(publisher_id) column. Note, that you could also name the column in your 'Book'-table differently -- like, say, 'Spongebob' or 'Patrick'. But for future use, you'd like naming conventions that tell what you might expect to find in a column. So you'd name columns for what they contain.
Second statement:
The problem is with the last portion of your statement, where there's a comma after the NOT NULL portion for column publisher_address.
(Part of) your statement:
publisher_address varchar2(60) not null, );
Try replacing that with:
publisher_address VARCHAR2(60) NOT NULL);
edit (note to self):
VARCHAR2 turns out to be a valid datatype in Oracle databases (see:
Oracle documentation)
For your first table, the Foreign Keys do not reference any table. For your second table, I would imagine that comma after your last column isn't helping anything.
So this is the answer.
CREATE table Book
(
book_title varchar (100) not null ,
book_genre char(60) not null,
Date_of_publish date not null,
user_code char(7) not null ,
publisher_id char (7) not null,
writer_id char(7) not null,
book_id char (7) primary key not null ,
CONSTRAINT book_writer_id_fk FOREIGN KEY(writer_id) REFERENCES writer(writer_id),
CONSTRAINT book_publisher_id_fk FOREIGN KEY(publisher_id) REFERENCES publisher(publisher_id)
);
CREATE table publisher
(
publisher_id char (7) primary key not null,
publisher_name char(20) not null,
publisher_number char(10) not null,
publisher_email varchar2(60) not null,
publisher_address varchar2(60) not null
);
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'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);