Oracle® Database PL/SQL Language Reference 11g Release 2 (11.2) Part Number E25519-05 |
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The ALTER
TRIGGER
statement enables, disables, compiles, or renames a database trigger.
Note:
This statement does not change the declaration or definition of an existing trigger. To redeclare or redefine a trigger, use the "CREATE TRIGGER Statement" with theOR
REPLACE
clause.LNPLS1890Topics
If the trigger is in the SYS
schema, you must be connected as SYSDBA
. Otherwise, the trigger must be in your schema or you must have ALTER
ANY
TRIGGER
system privilege.
In addition, to alter a trigger on DATABASE
, you must have the ADMINISTER
DATABASE
TRIGGER
system privilege.
LNPLS1410alter_trigger ::=
LNPLS1411compiler_parameters_clause ::=
LNPLS1412schema
Name of the schema containing the trigger. Default: your schema.
LNPLS1413trigger
Name of the trigger to be altered.
LNPLS1414ENABLE
Enables the trigger.
LNPLS1891DISABLE
Disables the trigger.
LNPLS1415RENAME TO new_name
Renames the trigger without changing its state.
When you rename a trigger, the database rebuilds the remembered source of the trigger in the USER_SOURCE
, ALL_SOURCE
, and DBA_SOURCE
static data dictionary views. As a result, comments and formatting may change in the TEXT
column of those views even though the trigger source did not change.
LNPLS1892COMPILE
Recompiles the trigger, whether it is valid or invalid.
First, if any of the objects upon which the trigger depends are invalid, the database recompiles them.
If the database recompiles the trigger successfully, then the trigger becomes valid. Otherwise, the database returns an error and the trigger remains invalid.
During recompilation, the database drops all persistent compiler switch settings, retrieves them again from the session, and stores them after compilation. To avoid this process, specify REUSE
SETTINGS
.
LNPLS1893DEBUG
Has the same behavior for a trigger as it does for a function. See "DEBUG".
See Also:
Oracle Database Advanced Application Developer's Guide for information about debugging a trigger using the same facilities available for stored subprogramsLNPLS1419REUSE SETTINGS
Has the same behavior for a trigger as it does for a function. See REUSE SETTINGS.
LNPLS1418compiler_parameters_clause
Has the same behavior for a trigger as it does for a function. See the ALTER
FUNCTION
"compiler_parameters_clause".
LNPLS1420Disabling Triggers: Example The sample schema hr
has a trigger named update_job_history
created on the employees
table. The trigger fires whenever an UPDATE
statement changes an employee's job_id
. The trigger inserts into the job_history
table a row that contains the employee's ID, begin and end date of the last job, and the job ID and department.
When this trigger is created, the database enables it automatically. You can subsequently disable the trigger with this statement:
ALTER TRIGGER update_job_history DISABLE;
When the trigger is disabled, the database does not fire the trigger when an UPDATE
statement changes an employee's job.
LNPLS1421Enabling Triggers: Example After disabling the trigger, you can subsequently enable it with this statement:
ALTER TRIGGER update_job_history ENABLE;
After you reenable the trigger, the database fires the trigger whenever an UPDATE
statement changes an employee's job. If an employee's job is updated while the trigger is disabled, then the database does not automatically fire the trigger for this employee until another transaction changes the job_id
again.
LNPLS1894In this chapter:
LNPLS1895In other chapters: