integer primary/foreign key vs. varchar(255) primary/foreign key
Is there any principal performance (or some other) difference between using
the integer primary/foreign key and using the string (varchar(255)) keys in
queries that use tables joins?
Server is Sybase SQL Anywhere 5.5.04
Yes! The primary key will only be made up of 12 bytes. By using an
integer you ensure that your entire column is in the key.
Jim Egan [TeamPS]
Dynamic Data Solutions, Inc. http://www.dyn-data.com
Enterprise Applications in Your F...Primary key/Foreign key again
Thanks, Nat and David.
Under "SQL Anywhere", I get into ISQL to use "ALTER TABLE" command
to add my primary key:
ALTER TABLE Client
ADD PRIMARY KEY (SYSID)
I got an error: user 'dba' has the row in 'Client' locked.
How can I release the locking condition?
Click on another table in Sybase Central. Is suspect this is the issue.
Jaguar Product Team
John Chyan wrote:
> Thanks, Nat and David.
> Under "SQL Anywhere", I get into ISQL to use "ALTER TABLE" command
> to add my primary key:
...Primary Key/Foreign Key
Can I use SQL Commands to add Primary key or reference keys to existed
tables? (Not a new table, that's why I can't use CREATE TABLE command.)
If does, could someone give me some sample codes? Thanks.
What you need is the ALTER TABLE statement. Look for it in SQLA help for the
John Chyan wrote in message <35A4FF5D.5F192806@dissol.com>...
>Can I use SQL Commands to add Primary key or reference keys to existed
>tables? (Not a new table, that's why I can't use CREATE TABLE command.)
>If does, could someone ...Primary key
I've got a modeling problem betwin a conceptual model and a physical model
and espacially about the foreign key.
See below the illustrated exemple of the problem :
-Whether the entity � ARTICLE � with two informations : CODE & WORDING
-Whether the entity � UNITE � with two informations : CODE & WORDING
An article has necesseraly three unity, the unity of command, of storage and
These three unity can be differents.
The generated physical model doesn't suitable me.
How ...primary key and foreign Key????
Hi i have 2 table.. Table1UID Username1 AB2 CD3 DD Table 2ITEM Price UIDPOO1 20.00 1POO2 10.00 2POO3 15.00 1 Now i am letting the Admin to delete the user in table1But since UID 1 and 2 are ...Keys, keys,keys...
Just installed PGP 6.5.8 and all is running fine, so far :-)
Question: When I opened the PGP Keys window for the first time, apart
from the *Create Key* wizard, there are about 50 odd keys belonging to
various and sundry at NAI.
Were these supplied for a purpose or only for illustration? Is there any
reason they could not or should no be deleted?
Question 2: I sent someone an encrypted test message using that person's
public key. It went off fine except, I am left with only the encrypted
eMail. What setting should I change in order for my eMail client (Outlook
2000) ...Primary key
> Je me permet de soliciter une aide sur poweramc V8.
> Je suis en charge d'un projet ERP et je me pose la question suivante sur
> exemple de mod�lisation.
> Entit� : ARTICLE
> information : Code article
> Information : Libell� article
> Entit� : Unit�
> Information : Code unit� (exemple : Kg, palette, m2...)
> information : Libell� unit�
> Un article a 3 unit�s, unit� de stockage, unit� de vente et unit� d'achat.
> Ces trois unit�s peuvent �tre diff�rentes.
> Dans mon MCD, j'...composite primary key and foreign key
I refer a composite primary key of a master table, I
have to refer all the fields of the composite primary key. But how to
partially refer the composite primary key in a child table? For
example, if PARENT table has primary key (A,B,C), how to create a foreign key
in CHILD table which will refer only (A,B) fields of Table1?
Please refer to the following description:
In a foreign key reference, a link is created between two tables when the column or columns that hold the primary key value for one table are referenced by the column or columns in another table...Foreign keys have the same columns as primary key
After upgrading from AppModeler 6.0 to 6.1 when I check my PDM I'm getting
the following warning messages on a lot of columns: Foreign Keys have the
same columns as primary key. The suggested correction doesn't help much.
Can some one explain this warning to me? It seems that when the primary key
of one table is a foreign key from another table this warning is poping up.
Any help appreciated.
James L. Knowlton
President and Programer/Analyst
Law Enforcement Automated Data Systems, Inc
begin 666 James L. Knowlton.vcf
M0D5'24XZ5D-!4D0-&q...No primary key value for foreign key
I tried to:
alter table sa.shipitems
add foreign key FK_SHIPITEM_REFERENCE_OITEMS (oitemsid)
references sa.oitems (oitemsid)
on update cascade
on delete restrict
but got this error:
No primary key value for foreign key 'FK_SHIPITEM_REFERENCE_OITEMS' in table
What does it mean and how to round this problem?
fyi, here is the definition of both table
/* Table: shipitems */
/*===============================...Primary Key/Foreign Key relationship errors
So I am having trouble getting Dynamic Data to set up my SQL Data properly. For some reason, it is not reading the primary key/foreign key relationships correctly. Here is an example of the warning message I am getting:
Warning 1 DBML1062: The Type attribute 'UpdatedInfo' of the Association element 'Location_UpdatedInfo' of the Type element 'Location' does not have a primary key. No code will be generated for the association. 0 0 Warning 2 DBML1062: The Type attribute 'UpdatedInfo' of the As...Foreign key constraint to a composite primary key
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?
Yes u can give foreign key constraint to the table 2 but the composite primary should be there in foreign table. For eg. table 1 has 2 columns (e-id, e-name) as composite primary key then table2 must have (e-id,e-name) as the columns (maybe with different headings) but the foreign key can be set.Sagar Virani
The syntax for a referential constraint is: &nb...Foreign key duplicates part of primary key
I have the following entities
with the following identifiers
Employment - dependent of Employee and Payroll, Many to one relationship to
Termination - dependent of Payroll
When I generate the physical model I get the following tables
and primary keys, foreign keys
Termination - dependent of Payroll
Pa...Clustered Primary Key and Foreign Key: T-SQL
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 ( course...