Update table where there is FOREIGN KEY reference

  • Want to update t4 table

    but update fails as there is relationship between tables. Right there is one to many relationship between T3 and T4

    CREATE TABLE T3

    (

    FirstName NVARCHAR(255),

    MiddleName NVARCHAR(255),

    LastName NVARCHAR(255),

    ContactID INT,

    CONSTRAINT pk_T3_pid PRIMARY KEY(ContactID)

    )

    GO

    CREATE TABLE T4

    (

    ContactID INT,

    SalesOrderID INT,

    TotalDue MONEY,

    CONSTRAINT pk_T4_sid PRIMARY KEY(SalesOrderID),

    CONSTRAINT fk_T4_sid FOREIGN KEY(ContactID) REFERENCES T3(ContactID)

    )

    GO

    I want to update T4 table for ContactID= 1 where i want to update SalesOrderID and TotalDue

    How to go ahead with this kind of update

  • You may disable constraint like that

    alter table dbo.T4 nocheck constraint fk_T4_sid

    and do what you want, but, be aware of performance problems. I blogged about it here[/url] (unfortunatelly it is only in russian, but t-sql and plans talk for them selfes).

    To have all the benefits of FK, your FK should be trusted, that means, that there should be a solid integrity of data and no missing values of fk column for pk.


    I am really sorry for my poor gramma. And I hope that value of my answers will outweigh the harm for your eyes.
    Blog: http://somewheresomehow.ru[/url]
    Twitter: @SomewereSomehow

Viewing 2 posts - 1 through 1 (of 1 total)

You must be logged in to reply to this topic. Login to reply