Use of QT SQLite triggers

First, let's take a look at the structure of the basic trigger.
: ---------- SQL trigger -------------------------------------------------
1. Delete
Create trigger [delete_topalexa] on [DBO]. [tb_website]
For Delete
As
Begin transaction
Delete from tb_alexa where websiteid = (select websiteid from deleted)
Delete from tb_top100 where websiteid = (select websiteid from deleted)
If (@ error <> 0) -- if an error exists
Begin
Rollback transaction -- rollback
End
Commit transaction -- submit a transaction
2. Update
Create trigger test_ OK
On OK
For update
As
If Update (name)
Begin
Update sname set sname. s_name = OK. name from OK, sname
Where sname. n_id = OK. n_id
End

 

Note: keywords are marked in uppercase blue, and italics represent user strings.

Triggername ------------- trigger name

Maintablename ------ name of the primary table

Childtablename ------- subtable name

Ctbid ------------------------- fields of the sub-table

Mid -------------------------- comparison fields of the master table

: ---------- SQLite trigger -------------------------------------------------
1. Delete
Create triggerTriggernameAfter delete onMaintablenameFor each row
Begin
Delete fromChildtablenameWhereCtbid= Old.Mid;
End;

2. Update
Create triggerTriggernameAfter update onMaintablename 
For each row
Begin
UpdateChildtablenameSetCtbid
= New. Mid
WhereChildtablename.Ctbid=
Old. Mid;
End;