Need a trigger to update same row after insert

Question

Hi Everyone,

I am looking to create a trigger that will update a row or record right after that record has added to the database. We used to call this an after insert trigger.

Specifically, after the row has been inserted, I would like to have the uniqueidentifier field (named Contact_GUID) value put in a variable that will get the string equivalent of the variable and re-insert it into the same row (that field is called Str_Contact_GUID).

The reason I do this is that I can pass the string equivalent to other applications and still query the same row.

I know how to translate the uniqueidentifier into a string equivalent.(I have the code for that)

I only need the code to update the same row that would have been just inserted.

Thanks so much,

Jon

Answer 1

 I would like to have the uniqueidentifier field (named Contact_GUID) value put in a variable that will get the string equivalent of the variable and re-insert it into the same row (that field is called Str_Contact_GUID).

Why do you have to do that? Here is a simple GUID conversion to varchar:

SELECT GUIDSTRING=CONVERT(varchar(37),newid())
-- B7173239-2408-44EE-A29D-D5DA59E93D67

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Kalman Toth, SQL Server & Business Intelligence Training; SQL SERVER BEST PRACTICES

Answer 2

Agree with Kalman. 

You only need to set a default value for the column, 

see this e.g

create table t1(id int,ncid varchar(37) default (CONVERT(varchar(37),newid())))
  
insert into t1(id) values(1),(2),(3)

select * from t1

vt

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