Updating avg database
The variables and subprograms exist for the duration of the triggering statement.The syntax for creating the simplest compound DML trigger on a noneditioning view is: A compound DML trigger created on a table or editioning view has at least one timing-point section in Table 9-2.Compound DML triggers help program an approach where you want the actions that you implement for the various timing points to share common data.A simple or compound DML trigger that fires at row level can access the data in the row that it is processing.Without a column list, the trigger fires when any column of the associated table is updated.Example 9-1 Trigger Uses Conditional Predicates to Detect Triggering Statement This example creates a DML trigger that uses conditional predicates to determine which of its four possible triggering statements fired it.Two common uses of compound triggers are: The optional declarative part of a compound trigger declares variables and subprograms that all of its timing-point sections can use.
If the trigger is created on a schema or the database, then the triggering event is composed of either DDL or database operation statements, and the trigger is called a clause that specifies a SQL condition that the database evaluates for each row that the triggering statement affects.
Salary%TYPE INDEX BY VARCHAR2(80); Department_Avg_Salaries Department_Salaries_t; BEFORE STATEMENT IS BEGIN SELECT AVG(e. Department_ID, -1) BULK COLLECT INTO Avg_Salaries, Department_IDs FROM Employees e GROUP BY e. (The database does not support declarative referential constraints between tables on different nodes of a distributed database.) Disable this foreign key constraint to prevent the corresponding ).