Update field in INSERTED inside trigger

  • Hello,

    I have a table that constantly has rows inserted, and one of the fields is always empty. I want to create an Insert trigger on the table and populate the empty field with data extracted from several of the other fields.

    e.g.

    CREATE TRIGGER tr_PutInValue ON MyTable

    FOR INSERT

    AS

    update INSERTED

    set EmptyField = DataField1 + ':' + DataField2 + ':' + GetDate()

    But when I try to create this trigger, SQL tells me

    Server: Msg 286, Level 16, State 1, Procedure trI_syslog, Line 119

    The logical tables INSERTED and DELETED cannot be updated.

    If I can't modify values in the Inserted table, then how can I achieve what I want?

    -Steve

  • inserted/updated tables are just views of the log.  when you want to update the value in the record, update against the real table name joining to "inserted" to identify which rows were modified.

    But it would be better to do what you want done in the insert statement.

  • Thanks for the advice, John.  The inserts are being done by a 3rd-party application that I have no control over, so hence using the trigger.

    Unfortunately the table has no indexes, so to join INSERTED with the main table in an insert trigger I believe would cause a huge performance hit (the main table will have hundred of thousands of rows, and has no distinguishable unique fields to use for a primary key)

    Most likely candidate for an index is the DateTime field called DateTimeLocal. It is not unique, but the most rows with identical values I've seen so far is less than 100, so a non-unique index on this field could work.

    Wish me luck!

     

  • Why don't you try to add an identity column?

    For best performance make it a clustered primary key.

  • I have an example

    create TRIGGER InsertarPeriodoForUpdate

    ON dbo.calificacion_IQA

    for update

    AS

    BEGIN

    SET NOCOUNT ON;

    declare @id int

    declare @mes int

    select @mes=mes_calificadcion, @id = id_calificacion_iqa from updated

    if @mes=1 or @mes = 2 or @mes = 3

    begin

    Update dbo.calificacion_IQA

    set cuarto = 1

    where id_calificacion_iqa=@id

    end

    if @mes=4 or @mes = 5 or @mes = 6

    begin

    Update dbo.calificacion_IQA

    set cuarto = 2

    where id_calificacion_iqa=@id

    end

    if @mes=7 or @mes = 8 or @mes = 9

    begin

    Update dbo.calificacion_IQA

    set cuarto = 3

    where id_calificacion_iqa=@id

    end

    if @mes=10 or @mes = 11 or @mes = 12

    begin

    Update dbo.calificacion_IQA

    set cuarto = 4

    where id_calificacion_iqa=@id

    end

    END

    GO

  • sipadu (7/29/2013)


    I have an example

    create TRIGGER InsertarPeriodoForUpdate

    ON dbo.calificacion_IQA

    for update

    AS

    BEGIN

    SET NOCOUNT ON;

    declare @id int

    declare @mes int

    select @mes=mes_calificadcion, @id = id_calificacion_iqa from updated

    if @mes=1 or @mes = 2 or @mes = 3

    begin

    Update dbo.calificacion_IQA

    set cuarto = 1

    where id_calificacion_iqa=@id

    end

    if @mes=4 or @mes = 5 or @mes = 6

    begin

    Update dbo.calificacion_IQA

    set cuarto = 2

    where id_calificacion_iqa=@id

    end

    if @mes=7 or @mes = 8 or @mes = 9

    begin

    Update dbo.calificacion_IQA

    set cuarto = 3

    where id_calificacion_iqa=@id

    end

    if @mes=10 or @mes = 11 or @mes = 12

    begin

    Update dbo.calificacion_IQA

    set cuarto = 4

    where id_calificacion_iqa=@id

    end

    END

    GO

    Not only is this thread 9 years old your code is broken on a number of levels. There is no "updated" in triggers in sql server. And even worse is that your code will not support multiple rows. The logic posted is entirely to flawed to even have a chance at being correct.

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