I've checked that none of the two tables has any foreign keys. I've checked that they both have Id of type uniqueidentifier. I runt the script and get this eror.
ALTER TABLE [dbo].[Records]
ADD CONSTRAINT [FK_dbo.Records_dbo.Users_UserId]
FOREIGN KEY ([UserId])
REFERENCES [dbo].[Users] ([Id])
--ON DELETE CASCADE
The ALTER TABLE statement conflicted with the FOREIGN KEY constraint "FK_dbo.Records_dbo.Users_UserId". The conflict occurred in database "MyDb", table "dbo.Users", column 'Id'.
Not sure how to troubleshoot it... Tested both with and without the cascade...
It must be something to do with the existing data. There must be some records conflicting the foreign key creation. Try to create the key on an empty schema to see if it works. Use WITH NOCHECK to not to check existing rows at the time of foreign key creation, if you need that data.
Most likely you have a UserId in the Records table that does not exist in the Users table. This will certainly happen if you've been using 0 or some other value as a "default" value.
Related
I have three tables as follows -
But when I add the foreign key reference, the relation is ( a straight line in the Database Diagram) not shown.
Following is the reference I wrote.
ALTER TABLE [dbo].EmployeeDesignation
ADD CONSTRAINT FK_EmployeeDesignation_Employee FOREIGN KEY (EmployeeId)
REFERENCES Employee (EmployeeId)
ON DELETE CASCADE
ON UPDATE CASCADE
;
ALTER TABLE [dbo].[EmployeeDesignation]
ADD CONSTRAINT FK_EmployeeDesignation_Designation FOREIGN KEY (DesignationId)
REFERENCES Designation (DesignationId)
ON DELETE CASCADE
ON UPDATE CASCADE
;
In addition, When I add another two tables (Department and EmployeeDepartment) I can see the relation in the diagram
The code for the reference is as follows --
ALTER TABLE [dbo].EmployeeDepartment
ADD CONSTRAINT FK_EmployeeDepartment_Department FOREIGN KEY (DepartmentId)
REFERENCES Department (DepartmentId)
ON DELETE CASCADE
ON UPDATE CASCADE
;
ALTER TABLE [dbo].EmployeeDepartment
ADD CONSTRAINT FK_EmployeeDepartment_Employee FOREIGN KEY (EmployeeId)
REFERENCES Employee (EmployeeId)
ON DELETE CASCADE
ON UPDATE CASCADE
;
What might be the reason That the later one showing relation line while the previous one is not showing?
Am I missing something?
Thanks !
Try closing SSMS and then reopening it again. Seems like the cache used by SSMS for some of functionality is not refreshed even upon closing and re-opening the database connection. check https://stackoverflow.com/a/4316415/364084
I am trying to add unique constraint as foreign key by this statement:
ALTER TABLE SOME_TABLE ADD(
CONSTRAINT FK_ID FOREIGN KEY (S_ID) REFERENCES OTHER_TABLE(O_ID) UNIQUE (S_ID)
);
I thought that this statement is correct, but all time I got "missing right parenthesis error". Probably I have wrong order of key words.
Could you give me advice how to create an unique constraint ?
I red this issue:
Add a unique constraint of a sql table as foreign key reference to an another sql table
but still I have problem with this.
First, you don't need parentheses. Second, this is two constraints and you might as well give both names:
ALTER TABLE SOME_TABLE
ADD CONSTRAINT FK_ID FOREIGN KEY (S_ID) REFERENCES OTHER_TABLE(O_ID);
ALTER TABLE SOME_TABLE
ADD CONSTRAINT UNQ_ST_S_ID UNIQUE (S_ID);
I've been looking over the following SQL code for awhile and just can't seem to find the problem. I'm relatively new to SQL, so I'm sure it's just something I'm overlooking. The error message I get is: ORA-01735: Invalid ALTER TABLE option.
Code:
ALTER TABLE PATIENT
(
ADD CONSTRAINT PProfileForeignKey
FOREIGN KEY (pProfileID) REFERENCES PATIENT_PROFILE(Profile_ID),
ADD CONSTRAINT InsForeignKey
FOREIGN KEY (pInsID) REFERENCES INSURANCE(Insurance_ID)
ON DELETE SET NULL
);
I have triple checked to make sure the foreign key column names and the referenced column names are correct.
seems The parentheses are in wrong place
ALTER TABLE PATIENT
ADD (CONSTRAINT PProfileForeignKey
FOREIGN KEY (pProfileID) REFERENCES PATIENT_PROFILE(Profile_ID),
CONSTRAINT InsForeignKey
FOREIGN KEY (pInsID) REFERENCES INSURANCE(Insurance_ID)
ON DELETE SET NULL);
I'm brand new to using Oracle SQLDeveloper and I'm working on a college project right now. I keep trying to add foreign key constraints to my tables(which already hold the foreign key as an attribute) so Im using ALTER like this:
alter table applies
add constraint e_number foreign key (e_number)
references student (e_number);
where e_number is the primary key in a table called student. The student table's e_number has the primary key constraint and also has an index that was auto-generated where it says UNIQUE under the UNIQUENESS column in the indexes tab. Whenever I try and create a foreign key for any of my tables I'm getting this same error everytime:
Error starting at line : 1 in command -
alter table applies
add constraint e_number foreign key (e_number)
references student (e_number)
Error report -
SQL Error: ORA-02264: name already used by an existing constraint
02264. 00000 - "name already used by an existing constraint"
*Cause: The specified constraint name has to be unique.
*Action: Specify a unique constraint name for the constraint.
I'm a bit confused and have been reading about unique on several sites but still don't get it. When I call an ALTER I can either specify a FOREIGN key or specify a UNIQUE key. Am I supposed to ALTER unique and then ALTER foreign? What am I doing wrong?
It's because you already have a key named e_number. Try:
alter table applies
add constraint applies_student_e_number foreign key (e_number)
references student (e_number);
I have a table named master_employee with a column empid as the primary key, and it has 12 rows in it. This empid has been mapped as a foreign key to another table named dep_child. I want to delete the 12 records in the master_employee table but I was unable to do it.
You were unable to do the deletes from master_employees, as there is a referential integrity with dep_child. You would need to either disable the constraint or delete the records from dep_child, before being able to delete records from master_employees
Add this constraints to your master_employee table
ALTER TABLE "master_employee"
ADD CONSTRAINT "fk_emp11"
FOREIGN KEY ("emp_id")
REFERENCES "dep_child" ("emp_id")
ON DELETE CASCADE;