confusion in setting up superkey

  • deba_20032004

    Default port

    Points: 1476

    Dear Sir,

    I am in great trouble, my problem is I have a vendor Table

    which consist of some fields. I explaining the structure below

    Table<Vendor>

    --------------

    fields name

    -----------

    PKID int

    VENDORID int

    VENDORNAME varchar (50)

    ADDRESS varchar(50)

    CITY varchar(15)

    I have set Primary key on PKID (cluster index)

    I have set non cluster index on (VENDORID,VENDORNAME/ADDRESS) FIELDS

    now I want to set superkey on (VENDORID+ADDRESS+CITY) which identify unique record.

    is it right structure for creating index

    please give me suggestion

    thanks in advance

    Debasis

  • Andrew G

    SSChampion

    Points: 12687

    You can create a unique non clustered index on (VENDORID+ADDRESS+CITY) since your primary key is already specified. You can specify a unique key constraint when creating the table also.

  • ChrisM@home

    SSC-Insane

    Points: 24260

    deba_20032004 (10/15/2012)


    Dear Sir,

    I am in great trouble, my problem is I have a vendor Table

    which consist of some fields. I explaining the structure below

    Table<Vendor>

    --------------

    fields name

    -----------

    PKID int

    VENDORID int

    VENDORNAME varchar (50)

    ADDRESS varchar(50)

    CITY varchar(15)

    I have set Primary key on PKID (cluster index)

    I have set non cluster index on (VENDORID,VENDORNAME/ADDRESS) FIELDS

    now I want to set superkey on (VENDORID+ADDRESS+CITY) which identify unique record.

    is it right structure for creating index

    please give me suggestion

    thanks in advance

    Debasis

    Why does your vendor table have both a PKID and a VendorID?


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  • Dwain Camps

    SSC Guru

    Points: 86883

    ChrisM@home (10/15/2012)


    deba_20032004 (10/15/2012)


    Dear Sir,

    I am in great trouble, my problem is I have a vendor Table

    which consist of some fields. I explaining the structure below

    Table<Vendor>

    --------------

    fields name

    -----------

    PKID int

    VENDORID int

    VENDORNAME varchar (50)

    ADDRESS varchar(50)

    CITY varchar(15)

    I have set Primary key on PKID (cluster index)

    I have set non cluster index on (VENDORID,VENDORNAME/ADDRESS) FIELDS

    now I want to set superkey on (VENDORID+ADDRESS+CITY) which identify unique record.

    is it right structure for creating index

    please give me suggestion

    thanks in advance

    Debasis

    Why does your vendor table have both a PKID and a VendorID?

    Maybe he wants to be able to change the VendorID at some future time?


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  • Eugene Elutin

    SSC Guru

    Points: 59322

    ...

    now I want to set superkey on (VENDORID+ADDRESS+CITY) which identify unique record.

    ...

    Why three of them? Are you saying that VENDORID in your VENDOR table is not unique by itself?

    Or, you want to say that the same Vendor can have different addresses or at the same address you may hold multiple vendors? If so, you better create separate Address and VendorAddress tables to this data in RDBMS way. Address table will have AddressId and address details and VendorAddress will have VendorId and AddressId as a composite PK?

    Or, at least, just have separate VendorAddress table to store multiple vendor addresses in your way. Still, it will be way better than storing multiple records of the same vendor in Vendor table...

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