Sql updating a table from another table erinslegscene not updating
If a triggering statement omits a column list, the trigger fires when any column of the associated table is updated.
Because the trigger uses the clause, it might be executed multiple times, such as when updating or deleting multiple rows.
You might omit this clause if you just want to record the fact that the operation occurred, but not examine the data for each row.
This type of trigger also provides an additional correlation name for accessing the parent row that contains the nested table being modified. SQL (the first part) declares variables and subprograms that timing-point sections can use.
When the trigger fires, the declarative part executes before any timing-point sections execute.
Table 9-1 summarizes the timing point sections of a compound trigger that can be defined on a table.