Create a SQL Trigger to alter multiple rows into another table? - sql

Question

I'm using databases to connect with PowerApps and PowerBI and I had a question about triggers.
I have a table (Table A) that contains three columns: ID, TotalQty & Date. I would like to create a trigger based on the three main row actions: Insert, Delete & Update.
Example: New row is inserted into Table A from PowerApps (ID = 1000000 & TotalQty = 3 & Date = Today)
This should fire the trigger three times to insert a row into Table B (with rows ID, QrderQty, and Date):
ID = 1000000, OrderQty = 1 of 3, Date = Today
ID = 1000000, OrderQty = 2 of 3, Date = Today
ID = 1000000, OrderQty = 3 of 3, Date = Today
Similarly, if the date column is updated on Table A for this row, I need the three corresponding rows to update their respective date values as well. Or if the row in Table A is deleted, I need the three rows to be removed.
Could anybody give me an example query of this?

Answer 1

You need to create a Trigger first this link contains some tutorial on how to create a trigger.
Then according to your question you need to do some kind of loop for generating values for the OrderQty, I have done a while loop in this answer that exists as part of TSQL
Assuming that you create TableA and TableB with following schemas:
create table [dbo].[TableA]
(
ID integer not null,
TotalQty integer not null,
Date Date not null
)
go
create table [dbo].[TableB]
(
ID integer not null,
OrderQty nvarchar(10) not null,
Date Date not null
)
go
You can create the trigger as follows to do the job for you:
CREATE TRIGGER [dbo].[InsertFromAToB]
ON [dbo].[TableA]
AFTER INSERT
AS
BEGIN
Declare #counter as integer;
set #counter=1;
Declare #qty as integer;
set #qty = (Select TotalQty from inserted);
While(#counter <= #qty)
Begin
Insert into TableB(ID,OrderQty,Date) select ID,(CONVERT(nvarchar(10),#counter) + ' of ' + Convert(nvarchar(10),#qty)) as OrderQty,Date From inserted
set #counter=#counter+1;
END
END