- What is instead of trigger in Oracle?
- How do you run a trigger?
- What is mutating error how do you avoid it?
- What is a mutating trigger in Oracle?
- What is a mutating table?
- What is Pragma Autonomous_transaction?
- What is trigger with example?
- What is trigger and its types?
- What are types of triggers in Oracle?
- What is the meaning of mutating?
- What are ref CURSORs in Oracle?
- What is Pragma Exception_init?
What is instead of trigger in Oracle?
What is an instead of trigger in Oracle.
An INSTEAD OF trigger is a trigger that allows you to update data in tables via their view which cannot be modified directly through DML statements.
When you issue a DML statement such as INSERT , UPDATE , or DELETE to a non-updatable view, Oracle will issue an error..
How do you run a trigger?
Running a TriggerIn the Databases folder in Enterprise Explorer, under the database connection profile, expand the navigation tree for the appropriate database and schema owner. … Expand the Tables folder, the table where the trigger is located, and then the Triggers folder.Right-click the trigger and select Run.More items…
What is mutating error how do you avoid it?
A mutating table error (ORA-04091) occurs when a row-level trigger tries to examine or change a table that is already undergoing change (via an INSERT, UPDATE, or DELETE statement). In particular, this error occurs when a row-level trigger attempts to read or write the table from which the trigger was fired.
What is a mutating trigger in Oracle?
The Oracle mutating trigger error occurs when a trigger references the table that owns the trigger, resulting in the “ORA-04091: table name is mutating, trigger/function may not see it” message.
What is a mutating table?
A mutating table is a table that is currently being modified by an UPDATE, DELETE, or INSERT statement, or it is a table that might need to be updated by the effects of a declarative DELETE CASCADE referential integrity constraint.
What is Pragma Autonomous_transaction?
The AUTONOMOUS_TRANSACTION pragma changes the way a subprogram works within a transaction. A subprogram marked with this pragma can do SQL operations and commit or roll back those operations, without committing or rolling back the data in the main transaction. … They pass information to the compiler.
What is trigger with example?
Trigger: A trigger is a stored procedure in database which automatically invokes whenever a special event in the database occurs. For example, a trigger can be invoked when a row is inserted into a specified table or when certain table columns are being updated.
What is trigger and its types?
Triggers are stored programs, which are automatically executed or fired when some events occur. Triggers are, in fact, written to be executed in response to any of the following events − A database manipulation (DML) statement (DELETE, INSERT, or UPDATE) A database definition (DDL) statement (CREATE, ALTER, or DROP).
What are types of triggers in Oracle?
There are five different types of Oracle Database triggers.Statement triggers are associated with a DML statement, such as DELETE , INSERT , or UPDATE , on a specified table or view. … Row triggers are fired for each row that is affected by an INSERT , UPDATE , or DELETE statement on a table.More items…
What is the meaning of mutating?
verb (used with object), mu·tat·ed, mu·tat·ing. to change; alter. Biology. to cause (a gene, cell, etc.) to undergo an alteration of one or more characteristics: The disease mutates the retina’s rod cells, and they slowly stop working. Phonetics. to change by umlaut.
What are ref CURSORs in Oracle?
Using REF CURSOR s is one of the most powerful, flexible, and scalable ways to return query results from an Oracle Database to a client application. A REF CURSOR is a PL/SQL data type whose value is the memory address of a query work area on the database. … A REF CURSOR refers to a memory address on the database.
What is Pragma Exception_init?
PRAGMA EXCEPTION_INIT associates a user-defined error code with an exception. A PRAGMA EXCEPTION_INIT declaration may be included in any block, sub-block or package. You can only assign an error code to an exception (using PRAGMA EXCEPTION_INIT) after declaring the exception.