How to combine three tables into a new table - sql

Question

all with the same column headings and I would like to create one singular table from all three.
I'd also, if it is at all possible, like to create a trigger so that when one of these three source tables is edited, the change is copied into the new combined table.
I would normally do this as a view, however due to constraints on the STSrid, I need to create a table, not a view.
Edit* Right, this is a bit ridiculous but anyhow.
I HAVE THREE TABLES
THERE ARE NO DUPLICATES IN ANY OF THE THREE TABLES
I WANT TO COMBINE THE THREE TABLES INTO ONE TABLE
CAN SOMEONE HELP PROVIDE THE SAMPLE SQL CODE TO DO THIS
ALSO IS IT POSSIBLE TO CREATE TRIGGERS SO THAT WHEN ONE OF THE THREE TABLES IS EDITED THE CHANGE IS PASSED TO THE COMBINED TABLE
I CAN NOT CREATE A VIEW DUE TO THE FACT THAT THE COMBINED TABLE NEEDS TO HAVE A DIFFERENT STSrid TO THE SOURCE TABLES, CREATING A VIEW DOES NOT ALLOW ME TO DO THIS, NOR DOES AN INDEXED VIEW.
Edit* I Have Table A,Table B and Table C all with columns ORN, Geometry and APP_NUMBER. All the information is different so
Table A (I'm not going to give an example geometry column)
ORN ID
123 14/0045/F
124 12/0002/X
Table B (I'm not going to give an example geometry column)
ORN ID
256 05/0005/D
989 12/0012/X
Table C (I'm not going to give an example geometry column)
ORN ID
043 13/0045/D
222 11/0002/A
I want one complete table of all info
Table D
ORN ID
123 14/0045/F
124 12/0002/X
256 05/0005/D
989 12/0012/X
043 13/0045/D
222 11/0002/A
Any help would be greatly appreciated.
Thanks

Answer 1

If the creation of the table is a one time thing you can use a select into combined with a union like this:
select * into TableD from
(
select * from TableA
union all
select * from TableB
union all
select * from TableC
) UnionedTables
As for the trigger, it should be easy to set up a after insert trigger like this:
CREATE TRIGGER insert_trigger
ON TableA
AFTER INSERT AS
insert TableD (columns...) select (columns...) from inserted
Obviously you will have to change the columns... to match your structure.
I haven't checked the syntax though so it might not be prefect and it could need some adjustment, but it should give you an idea I hope.

Answer 2

If IDs are not duplicated it ill be easy to achieve it, in another case you can must add a OriginatedFrom column. You also can create a lot of instead off triggers (not only for insert but for delete and update) but that a lazy excuse for not refactoring the app.
Also you must pay attention for any reference for the data, since its a RELATIONAL model is likely to other tables are related to the table you are about to drop.

Answer 3

This is the code for create the table D
drop table D;
Select * into D from (select * from A Union all select* from B Union all select * from C);

Answer 4

Its rather simple Just Create Table_D First
CREATE TABLE_D
(
ORN INT,
ID VARCHAR(20),
Column3 Datatype
)
GO
Use INSERT statement to insert records into this table SELECTing and using UNION ALL operator from other three table.
INSERT INTO TABLE_D (ORN , ID, Column3)
SELECT ORN , ID, Column3
FROM Table_A
UNION ALL
SELECT ORN , ID, Column3
FROM Table_B
UNION ALL
SELECT ORN , ID, Column3
FROM Table_C
Trigger
You will need to create this trigger on all of the tables.
CREATE TRIGGER tr_Insert_Table_A
ON TABLE_A
FOR INSERT
AS
BEGIN
SET NOCOUNT ON;
INSERT INTO TABLE_D (ORN , ID, Column3)
SELECT i.ORN , i.ID, i.Column3
FROM Inserted i LEFT JOIN TABLE_D D
ON i.ORN = D.ORN
WHERE D.ORN IS NULL
END
Read here to learn more about SQL Server Triggers