Can A Column Act As Both Primary Key And Foreign Key?
Sep 11, 2011Can a column act as both primary key and foreign key, if so what is script.
And can a table have more than one primary keys/foreign keys, if so what is the script.
Can a column act as both primary key and foreign key, if so what is script.
And can a table have more than one primary keys/foreign keys, if so what is the script.
I have come up with one scenarios where I have three table like Product, Services and Subscription. I have to create one table say Bundle where I can have some of the product id , service id and Subscription id , i.e. a bundle may contains sum prduct , services and subscription . How I can design these relations ?
View 3 Replies View RelatedOK - I have a two tables in a database. Table one contains an ID, 'oneID', field as the primary key. It is auto-incremented. Table two has ID field, 'twoID', as the primary key. This field also auto-increments. Table two also has 'oneID' as the foreign key.
Now, my question is, how do I get the foreign key in table two to auto-increment in conjuction with table one's primary key? They are after all the same data. Do I have to manually code to get table one data and save it to table two data?
thanks
I am having a little trouble getting this to work right, but have come a ways since I started this.......other tables created first and with no problems..... then these two with the last table being the problemI need to set one foreign key in the second table referencing the first table.But, the primary key is clustered with the two foreign keys and I get the error....There are no primary or candidate keys in the referenced table 'courseScores' that match the referencing column list in the foreign key 'FK_course'.CREATE TABLE dbo.courseScores ( courseId varchar(20) NOT NULL CONSTRAINT FK_courseId_courseStructure2 FOREIGN KEY (courseId) REFERENCES courseStructure (courseId),
studentId varchar(20) NOT NULL CONSTRAINT FK_studentId_students2 FOREIGN KEY (studentId) REFERENCES students (studentId),
CONSTRAINT PK_courseScore PRIMARY KEY CLUSTERED (courseId, studentId)
)CREATE TABLE dbo.objScores ( tmp int IDENTITY(1,1) PRIMARY KEY, objective varchar(50) NOT NULL, courseId varchar(20) NOT NULL CONSTRAINT FK_course FOREIGN KEY (courseId) REFERENCES courseScores (courseId) )
Once I get it working, then the tmp will be gone and then set 3 foreign keys as the clustered primary, fyi.Not sure how to reference half a primary key?Any help is greatly appreciated.....Thanks all,Zath
I'm currently using Oracle and receiving this error:
SQL Error: ORA-02291: integrity constraint (43437001.ATHLETE_FK1) violated - parent key not found
02291. 00000 - "integrity constraint (%s.%s) violated - parent key not found"
*Cause: A foreign key value has no matching primary key value.
*Action: Delete the foreign key or add a matching primary key.
When inserting this value:
INSERT INTO ATHLETE VALUES ('A001','TOM','HANKS','03-FEB-90','USA','C001');
With Tables:
CREATE TABLE ATHLETE(
ATHLETEID CHAR(4),
ATHLETEFIRSTNAME VARCHAR2(20),
ATHLETELASTNAME VARCHAR(20),
ATHLETEDOB DATE,
REPCOUNTRY VARCHAR2(12),
[Code] ......
I think the error is to do with the Athletes table (primary/foreign key)
How would I fix this in order to insert values without error?
I have an application in which i need to get the foreign key fieldsfrom a table and then get all the foreign keys primary key field fromthe linking table. Could some one tell me how i do this usingINFORMATION_SCHEMA. I have tried and can get the foreign keys but notsure how to get the associated primary keys.
View 1 Replies View Related
Hi,
In my table1, I have a composite primary key ssn+firstname+lastname.
In table2 I have ssn, firstname, lastname, col1. In table2 I want to create a foreign key which references table1 primary key?
table1 and table2 has the primary, foreign key relationships. Still table2 need primary key. In table2 Can I make the ssn+Firstname+Lastname as primary key? or one column id as auto increment?
Which is best way?
Thanks
I'm using MS SQL Server Studio Express 9.0. When selecting SQL Server Compact Edition, I'm able to create tables and primary keys with no problem. But how do I create a relationship with another table (foreign key)?
Bob K.
Hi All,
It seems I have been requested to carry out a complex query and the best way I think I can do this is with the use of a stored procedure. The problem is that I am not quite sure whether my SP is stated correctly and also how I would go about stating the SP in my VB.net code!
I would be ever so grateful if somebody could look over my SP code and possibly recommend a way of stating my code. My ability is limited so I would appreciate it if examples could be used with possible relations to my problem.
The Problem?
Tables:
1.tblRisk: Ref(pk), subject, status(fk), staff(fk), Dept(fk)
2.tblDept: Ref(pk), Department
The SP should state that Department should appear as the end result of the query when the page is loaded. So when a row is selected in tblRisk, dependant upon what the Dept is in that table, it then populates the department in which it is associated with from tblDept. I have left the SP below.
Many Thanks,
Kunal
CREATE PROCEDURE dbo.ShowMe @yourInputValue INTAS SELECT tblDept.Department FROM tblDept JOIN tblRisk ON tblDept.Ref = tblRisk.Dept WHERE tblDept.Ref = @yourInputValue RETURN 0GO
I have two tables: table 1 and table 2. The primary key of table is composite key of two collumns and table 2 is the child of parent table 1. Is it possible to create / define a foreign key constraint using a composite primary key?
View 10 Replies View RelatedHi,
How do I delete data which is a Foreign Key in another table?
For example;
string query = "DELETE * from user_details WHERE user_ID = '" +userID.Text+ "';
The user_ID is the Primary Key in the user_details table and also a Foreign Key in other tables.
Thank you. (:
I am having trouble dropping constraints(Primary and Foreign Keys). I would like to do so so I can truncate the tables and repopulate them. Any time I use the DROP CONSTRAINT #### on one table, I get an error message saying this is referenced in another table. Any help in how to drop the keys so I can truncate the tables in a database would be appreciated. I must be overlooking something simple. Thanks for the help.
Regards,
Mark
Hi,
I have a doubt, can anyone please clarify me.
I have created the following table,
create table z
(
eno int,
deptno char(2),
ename varchar(5),
constraint pk_eno_deptno primary Key(eno,deptno)
)
and I tried to establish a foreign key based on the above defined table. It's giving error,
create table z_dup
(
eno int FOREIGN KEY REFERENCES z(eno),
deptno char(2)
)
go
Error:-
*****
There are no primary or candidate keys in the referenced table 'z' that match the referencing column list in the foreign key 'FK__z_dup__eno__18CE1BA6'.Could not create constraint. See previous errors.
Even I tried to create a foreign key like the following,
create table z_dup
(
eno int FOREIGN KEY REFERENCES z(eno,deptno),
deptno char(2)
)
go
Error:-
********
More than one key specified in column level FOREIGN KEY constraint, table 'z_dup'.
Can anyone please help me to create a foreign key relation with the base table.
tks in advance,
Srinivasan
Hi,
I have two tables.
CREATE TABLE Service(
SERVId varchar (10) NOT NULL,
SERVName varchar (30) NOT NULL,
SERVDesc TEXT NULL,
PRIMARY KEY(SERVId)
)
CREATE TABLE New(
SERVId varchar (10) NOT NULL,
NDId varchar (10) NOT NULL,
NDName varchar (30) NOT NULL,
NDDesc text NULL,
PRIMARY KEY(SERVId,NDId)
FOREIGN KEY(SERVId)
REFERENCES Service(SERVId)
)
Msg 547, Level 16, State 2
DELETE statement conflicted with COLUMN REFERENCE constraint 'FK__Newdev__SERVId__4939E6D2'. The conflict occurred in database 'test', table 'New', column 'SERVId'
Command has been aborted.
The same problem occurs even if the second table i.e. new is declared as follows, i.e created with only one primary key:
CREATE TABLE New(
SERVId varchar (10) NOT NULL,
NDId varchar (10) NOT NULL,
NDName varchar (30) NOT NULL,
NDDesc text NULL,
PRIMARY KEY(NDId)
FOREIGN KEY(SERVId)
REFERENCES Service(SERVId)
)
what might be the problem? But the same relation works on MS Access.
Is there anyother way of declaring this kind of relationship i.e. primary and foreign key?Can anyone pl. help me in solving this problem of foreign key relation.
thanks in advance
-chaitra
I am trying to create a FK using a composite PK and here are the details that I want to achieve.
Table -A
Column A1 not null,
Column A2 not null
Primary key (A1, A2).
Table -B
Column B1 Primary key.
Column B2 not null
FK (B2) References A(A1).
When I try to do this I am getting some errors. Questions: First of all is this possible? if yes, then how I can create it.
I have a query that returns contacts connected to a client, but the problem is that it's only returning a result when a contact is associated with a client, even if the client does exist in the db. i want it to still return the client if the client exists.
SELECT * FROM clients, addressbook where clients.clientid = addressbook.clientid AND (clients.clientname LIKE '" . strtoupper($_GET['txtfname'])."%')
Be warned, index padding is not included in this, and I'm not sure the fillfactor setting is correct.
set nocount on
create table #PK(constraint_schema sysname not null, constraint_name sysname not null, sql varchar(4000) not null, constraint PK_#PK primary key clustered(constraint_schema, constraint_name))
create table #cols(constraint_schema sysname not null, constraint_name sysname not null, column_name sysname not null, ordinal_position int not null, constraint PK_#PKcol primary key clustered(constraint_schema, constraint_name, ordinal_position))
create table #FK(constraint_schema sysname not null, constraint_name sysname not null,
unique_constraint_schema sysname not null, unique_constraint_name sysname not null,
sql varchar(4000) not null, constraint PK_#FK primary key clustered(constraint_schema, constraint_name))
insert into #PK
select constraint_schema, constraint_name, 'ALTER TABLE ' + quotename(table_schema) + '.' + quotename(TABLE_NAME) +
' ADD CONSTRAINT ' + quotename(CONSTRAINT_NAME) +
' PRIMARY KEY ' + CASE WHEN si.indid<>1 THEN 'NON' ELSE '' END +
'CLUSTERED (>cols<) WITH FILLFACTOR=' + cast(si.OrigFillFactor as varchar) + ' ON ' + quotename(fg.groupname)
AS SQL
from INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC
INNER JOIN sysindexes si on TC.CONSTRAINT_NAME=si.name
inner join sysfilegroups fg on si.groupid=fg.groupid
WHERE CONSTRAINT_TYPE IN('PRIMARY KEY','UNIQUE')
insert into #fk
select c.constraint_schema, c.constraint_name, c.unique_constraint_schema, c.unique_constraint_name,
'ALTER TABLE ' + quotename(F.table_schema) + '.' + quotename(F.table_name) +
' ADD CONSTRAINT ' + quotename(F.constraint_name) +
' FOREIGN KEY(>cols<) REFERENCES ' + quotename(r.table_schema) + '.' + quotename(r.table_name) +
'(>rcols<)'
AS sql
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS F
INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C ON F.constraint_schema=C.constraint_schema AND f.constraint_name=c.constraint_name AND F.constraint_type='FOREIGN KEY'
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS R ON R.constraint_schema=C.unique_constraint_schema AND r.constraint_name=c.unique_constraint_name AND r.constraint_type in ('PRIMARY KEY','UNIQUE')
ORDER BY F.table_name, r.table_name
insert into #cols
select constraint_schema, constraint_name, COLUMN_NAME, ORDINAL_POSITION from INFORMATION_SCHEMA.KEY_COLUMN_USAGE
declare @ctr int, @max int, @delim varchar(1)
select @ctr=1, @max=max(ordinal_position), @delim='' from #cols
set nocount on
while @ctr<=@max
BEGIN
update P SET SQL=Replace(SQL, '>cols<', @delim + quotename(c.column_name) + '>cols<')
FROM #PK P INNER JOIN #cols C ON P.constraint_schema=C.constraint_schema AND P.constraint_name=C.constraint_name
WHERE C.ORDINAL_POSITION=@ctr
UPDATE F SET SQL=Replace(Replace(SQL, '>cols<', @delim + quotename(c.column_name) + '>cols<'), '>rcols<', @delim + quotename(r.column_name) + '>rcols<')
FROM #FK F INNER JOIN #cols C ON F.constraint_schema=C.constraint_schema AND F.constraint_name=C.constraint_name AND C.ordinal_position=@ctr
INNER JOIN #cols R ON F.unique_constraint_schema=R.constraint_schema AND F.unique_constraint_name=R.constraint_name AND C.ordinal_position=R.ordinal_position
select @ctr=@ctr+1, @delim=','
END
set nocount on
update #PK SET SQL=Replace(SQL, '>cols<', '')
update #FK SET SQL=Replace(Replace(SQL, '>cols<', ''), '>rcols<', '')
select sql from #PK
select sql from #FK
drop table #pk
drop table #fk
drop table #cols
I was trying a joining example provided in my book in which customer is a table and person is another table. The query provided in the book is this... USE AdventureWorks2012;
GO
SELECT c.CustomerID, c.PersonID, p.BusinessEntityID, p.LastName
FROM Sales.Customer AS c
INNER JOIN Person.Person AS p ON c.PersonID = p.BusinessEntityID;
This is the query that I did....
SELECT
c.CustomerID,p.FirstName,p.MiddleName,p.LastName
FROM
Sales.Customer AS c INNER JOIN Person.Person AS p
ON
c.CustomerID=p.BusinessEntityID
ORDER BY
p.BusinessEntityID;
Keys :-
Person Table
[PK_Person_BusinessEntityID]
[FK_Person_BusinessEntity_BusinessEntityID]
Customer Table
[PK_Customer_CustomerID]
[FK_Customer_Person_PersonID]
However,both of them gives a very different result set.But my question is why do we need to use the Customer.PersonID instead of Customer.CustomerID. Is it really important to use one primary key and one foreign,is there any specific reason why the book showed c.personId=p.BusinessEntityId.??
I have a DB with 100 tables. I was wondering if anybody knows a quick way to list primary and foreign key with the column name for all the tables.
Your help would make my life a lot easier
thanks
What is the simple way to remember Primary and foreign key?
Why is the ID column in a table declared as a integer datatype?
Hi there,
I'm facing a problem that errors occurred when i scheduled the job running a DTS, so i removed the primary & foreign key and the DTS is running successfully. Now, the problem is, i need to build back the primary and foreign key, can anyone assists me how to write a script to build back these two keys?
Please help!!
Thanks in advance!!
Hi all!
I'm just getting my feet wet with how encryption works in SQL 2005. With regards to the encryption of primary / foreign keys, I'm not entirely clear on the best approach. Below are three examples of typical table structures I currently have:
== Customers table ==
CustomerID (PK, int, Identity)
CustomerName (varchar)
== Orders table ==
OrderID (PK, int, Identity)
CustomerID (int, foreign key)
CreditCardNumber (varchar)
== OrderDetails table (1 to Many) ==
OrderID (PK/FK, int)
ItemNumber (PK, int)
ItemDescription (varchar)
The Customers and Orders tables use identity values as their primary keys. From what I can tell, CustomerID in the Customers table cannot be encrypted and OrderID in the Orders table cannot be encrypted because they are identity values. In these cases, would it be safer (in terms of security) to create a separate, meaningless identity key column in the Customers table and then remove the identity attribute from CustomerID so I can encrypt CustomerID?
Similarily in the OrderDetails table, OrderID and ItemNumber form a composite key. These values are important in that I don't want them to be tampered with. Am I better off creating a separate identity key column which becomes the table's primary key ... then encrypt both the OrderID and ItemNumber columns in this table?
Any ideas are appreciated.
Thank you,
Ben
Hey everyone,
I have just started getting into to SQL and am completely brand new to the whole concepts of relational databases. Someone on this forum pointed to the MSDN videos on LEARNVISUALSTUDIO.NET which have been very helpful. Unfortunately while learning about relational databases and looking at the program that I want to design and make using them, I have run into a pretty big wall, concerning the primary key and foreign key.
For my program, I am trying to save an object, and lets say the base class is SLIDE. Now SLIDE will store basically most of the information that I will ever want to store, such as timeCreated and mainText and slideID(primarykey). But there are other classes that derive from slide that will store just a bit more information than that because of what they are. Lets say there is a class derived from SLIDE called PERSON that stores its parentNode, which is to say something that this slide specifically belongs to and has a reference to. Now the tricky part is that in this program, every single slide can have a reference to another slide, that you would see displayed and that you could just click on and view if you wanted to.
Now relating what I just told about the classes in my program to a relation database standpoint is what confuses me. If I make a table SLIDE, it would hold incomplete data about the PERSON object, because that object has more data than SLIDE has. The answer to this was to make another table called PERSON, which would have more columns. But now we arrive at the big problem: The primary key called maybe SLIDEID would be different in this new PERSON table than in the other table called SLIDE (or any other derived class). Therefore the link between these tables is messed up. In my object orientated mind I am thinking of static class variables that would still stay constant for derived classes, so that when I make a PERSON slide it will increment off of the primary key of the SLIDE table. In other words, is there some sort of super TABLE that you can derive from, like an abstract class, where the primary keys of other tables can build off of because they will be used as the same type of reference to eachother.
If none of this made sense to the reader, I am greatly sorry. I do not really know what else I can say to convey to you the problem I have. Maybe its because I am so used to object orientated languages that this is making it so difficult to explain. If however you do understand what I am talking about, please think about it and help me find a solution to this problem. I am not an experienced programmer, but I do very much enjoy it and I am very excited about starting to make this program, and I have learned that before I start coding it is very important to have a very firm design in mind first.
Thank your for reading,
Jeremy
Hi all,
In my project i will have the data in a collection of objects, I need to update series of tables with foreign key relations
Right now my code looks like this
foreach(object obj in Objects){
int accountId=Account.Insert(obj.accountOpenDate,obj.accountName);//this will update the accounts table and returns account id which is a Identity column in Acccounts table
int DebtId=Debt.Insert(accountd,obj.debtamount,obj.debtbalance); this will update the Debts table and returns DebtId
///series of tables like above but all the relevant data comes from obj and in the Insert Methods i am using stored procedures to Insert the data into table
}
The no of objects varies from 1000 to 1 milliion,, with this approach its taking more time to update all the data. Please let me know if any alternative procedure to handle this kind of scenario.
Thanks
Regards
Prasad.
Ok, so I've broken down and decided to write myself an invoicing
program. I'd like to use GUID fields as the Primary Keys in my
table. Now, I basicly bill for two seperate items:
Deliverables and Services.
So, my Layout's gonna look something like
Create Table Invoice(
ID UniqueIdentifier Primary Key,
-- Other Data
);
Create Deliverable(
ID uniqueidentifier Primary Key,
ParentInvoice uniqueidentifier,
-- Other data);
--...
Im sure there are probems with that as it's written feel free to edify me as to what they are.
my questions are such:
1) Does a uniqueidentifier field automagically get a value?
2) If not how do I generate one in TSQL?
3) If so, what do I use to store my Foreign Keys.
4) How do I declare my Foreign key constraints?
I've following query which display the result as required, but I need to get the missing Primary Key Values which are not available in the result:
SELECTA.SignedByUserID, B.FullName, COUNT(A.OutletID) AS TotalSignups, DATENAME(Month, A.SignupDate) AS Month
FROMdbo.tblMer_Outlet AS A LEFT OUTER JOIN dbo.tblGen_Users AS B ON A.SignedByUserID = B.UserID
WHERE(A.SignupDate >= '2014-04-01 00:00:00' AND A.SignupDate <= '2014-04-30 23:59:59')
GROUP BY A.SignedByUserID, B.FullName, DATENAME(Month, A.SignupDate)
This Query returns the following result:
SignedByUserID FullName TotalSignups Month
--------------------------------------------------------
9 Babu Raj 16 April
11 Faheem 19 April
39 Fasil Abbas 16 April
29 Hafiz Suleman 10 April
[code]....
which does not have a signup for the month of April, but I need it to be available for this or any upcoming month. I need this orr all users, which does not exists in the context needs to be displayed in the result.
How can i find the primary field name and primary table name of a given foreign key.
For example
Table A:
IDa
Column1
Column2
Column3
Table B:
IDb
column1
column2
column3 <---- this is foreign key to table A's IDa
What i want to do is i pass input of tableB, column3 and i get name of Primary tableA and field name IDa. How is it possible to do in tsql ?
In a special request run, I need to update locker and lock tables in a sql server 2012 database, I have the following 2 table definitiions:
CREATE TABLE [dbo].[Locker](
[lockerID] [int] IDENTITY(1,1) NOT NULL,
[schoolID] [int] NOT NULL,
[number] [varchar](10) NOT NULL,
[lockID] [int] NULL
CONSTRAINT [PK_Locker] PRIMARY KEY NONCLUSTERED
[code]....
The locker table is the main table and the lock table is the secondary table. I need to add 500 new locker numbers that the user has given to me to place in the locker table and is uniquely defined by LockerID. I also need to add 500 new rows to the corresponding lock table that is uniquely defined in the lock table and identified by the lockid.
Since lockid is a key value in the lock table and is uniquely defined in the locker table, I would like to know how to update the lock table with the 500 new rows. I would then like to take value of lockid (from lock table for the 500 new rows that were created) and uniquely place those 500 lockids uniquely into the 500 rows that were created for the lock table.
I have sql that looks like the following so far:
declare @SchoolID int = 999
insert into test.dbo.Locker ( [schoolID], [number])
select distinct LKR.schoolID, A.lockerNumber
FROM [InputTable] A
JOIN test.dbo.School SCH ON A.schoolnumber = SCH.type and A.schoolnumber = @SchoolNumber
JOIN test.dbo.Locker LKR ON SCH.schoolID = LKR.schoolID
AND A.lockerNumber not in (select number from test.dbo.Locker where schoolID = @SchoolID)
order by LKR.schoolID, A.lockerNumber
I am not certain how to complete the rest of the task of placing lockerid uniquely into lock and locker tables?
how to find all primary key columns & foreign key columns in all database tables?
View 1 Replies View RelatedI want to create a table withmember id(primary key for Students,faculty and staff [Tables])and now i want to create issues[Tables] with foreign key as member idbut in references i could not able to pass on reference as orcondition for students, faculty and staff.Thank You,Chirag
View 3 Replies View RelatedIn a special request run, I need to update locker and lock tables in a sql server 2012 database, I have the following 2 table definitions:
CREATE TABLE [dbo].[Locker](
[lockerID] [int] IDENTITY(1,1) NOT NULL,
[schoolID] [int] NOT NULL,
[number] [varchar](10) NOT NULL,
[lockID] [int] NULL
CONSTRAINT [PK_Locker] PRIMARY KEY NONCLUSTERED
[Code] ....
The locker table is the main table and the lock table is the secondary table. I need to add 500 new locker numbers that the user has given to me to place in the locker table and is uniquely defined by LockerID. I also need to add 500 new rows to the corresponding lock table that is uniquely defined in the lock table and identified by the lockid.
Since lockid is a key value in the lock table and is uniquely defined in the locker table, I would like to know how to update the lock table with the 500 new rows. I would then like to take value of lockid (from lock table for the 500 new rows that were created) and uniquely place those 500 lockids uniquely into the 500 rows that were created for the lock table.
I have sql that looks like the following so far:
declare @SchoolID int = 999
insert into test.dbo.Locker ( [schoolID], [number])
select distinct LKR.schoolID, A.lockerNumber
FROM [InputTable] A
JOIN test.dbo.School SCH ON A.schoolnumber = SCH.type and A.schoolnumber = @SchoolNumber
JOIN test.dbo.Locker LKR ON SCH.schoolID = LKR.schoolID
AND A.lockerNumber not in (select number from test.dbo.Locker where schoolID = @SchoolID)
order by LKR.schoolID, A.lockerNumber
I am not certain how to complete the rest of the task of placing lockerid uniquely into lock and locker tables? Thus can you either modify the sql that I just listed above and/or come up with some new sql that will show me how to accomplish my goal?
I've attempted to identify a primary and foreign key in these two tables, but I am getting a bunch of errors re duplicate keys and column names needing to be unique.Perhaps the primary and foreign key I have identified don't meet the criteria?
CREATE TABLE StockNames
(
-- Added Primary key to [stock_symbol]
[stock_symbol] VARCHAR(5) NOT NULL CONSTRAINT PK_stock_symbol PRIMARY KEY,
[stock_name] VARCHAR(150) NOT NULL,
[stock_exchange] VARCHAR(50) NOT NULL,
[code].....
Is there anyway to get the order in which data to be import on to tables when they have primary and Foreign Key relations?
For ex:We have around 170 tables and when tries to insert data it will throw error stating table25 data should be inserted first when we insert data in table 25 it say 70 like that.