Trigger updating column chance for love dating network
FOR EACH ROW implies that the SQL statements specified in the trigger may be executed (depending on the WHEN clause) for each database row being inserted, updated or deleted by the statement causing the trigger to fire.
Both the WHEN clause and the trigger actions may access elements of the row being inserted, deleted or updated using references of the form "NEW.column-name" and "OLD.column-name", where column-name is the name of a column from the table that the trigger is associated with.
*/ select @row = @@rowcount if update (title_id) begin if (select distinct inserted.title_id from inserted) is null begin rollback transaction print "No, the old title_id must be in" print "salesdetail." end else if (select count(*) from titles, inserted where titles.title_id = inserted.title_id) !
check_updates are PL/Perl trigger functions to allow/deny certain type of table updates.
This module contains several function implementing rules that restrict certain subset of update commands on a table.
These functions are designed to be set as on update per-row triggers on a table.
The CREATE TRIGGER statement is used to add triggers to the database schema.You can use the same trigger name because the modified trigger replaces the old trigger when you create it again.create trigger stopupdatetrig on titles for update as if update (title_id) and datename(dw, getdate()) in ("Saturday", "Sunday") begin rollback transaction print "We do not allow changes to" print "primary keys on the weekend!A primary key is the unique identifier for its row and for foreign-key rows in other tables.Generally, you should not allow updates to primary keys. create trigger cascade_utrig on titles for update as if update(title_id) begin update titleauthor set title_id = inserted.title_id from titleauthor, deleted, inserted where deleted.title_id = titleauthor.title_id update roysched set title_id = inserted.title_id from roysched, deleted, inserted where deleted.title_id = roysched.title_id update salesdetail set title_id = inserted.title_id from salesdetail, deleted, inserted where deleted.title_id = salesdetail.title_id end An attempt to update a primary key should be taken very seriously.