what is trigger
Answer / ranganath
In a DBMS, a trigger is a SQL procedure that initiates an
action (i.e., fires an action) when an event (INSERT,
DELETE or UPDATE) occurs. Since triggers are event-driven
specialized procedures, they are stored in and managed by
the DBMS. A trigger cannot be called or executed; the DBMS
automatically fires the trigger as a result of a data
modification to the associated table. Triggers are used to
maintain the referential integrity of data by changing the
data in a systematic fashion.
Each trigger is attached to a single, specified table in
the database.
Triggers can be viewed as similar to stored procedures in
that both consist of procedural logic that is stored at the
database level. Stored procedures, however, are not event-
drive and are not attached to a specific table as triggers
are. Stored procedures are explicitly executed by invoking
a CALL to the procedure while triggers are implicitly
executed. In addition, triggers can also execute stored
procedures.
A trigger can also contain INSERT, UPDATE and DELETE logic
within itself, so when the trigger is fired because of data
modification it can also cause another data modification,
thereby firing another trigger. A trigger that contains
data modification logic within itself is called a nested
trigger.
| Is This Answer Correct ? | 20 Yes | 1 No |
What is query and its types?
How to write a query with a right outer join in ms sql server?
How to store pdf file in sql server?
1 Answers CarrizalSoft Technologies, College School Exams Tests, TATA,
Explain isolation levels that sql server supports?
How will you go about resolving deadlocks?
How do I shrink an ldf file?
is it important for a database administrator to understand the operating system and file access? : Sql server administration
how to retrive only second row from table in sql server 2000?
difference between Clustered index and non clustered index ?
I have a table EMP in which the values will be like this EmpId Ename Sal DeptId 11 Ram 10000 10 11 Ram 10000 10 22 Raj 20000 20 22 Raj 20000 20 33 Anil 15000 30 33 Anil 15000 30 I want to delete only duplicate Rows. After Delete I want the output like this EmpId Ename Sal DeptId 11 Ram 10000 10 22 Raj 20000 20 33 Anil 15000 30
What is the difference between stored procedure and user defined functions?
What is mssql?
Oracle (3253)
SQL Server (4518)
MS Access (429)
MySQL (1402)
Postgre (483)
Sybase (267)
DB Architecture (141)
DB Administration (291)
DB Development (113)
SQL PLSQL (3330)
MongoDB (502)
IBM Informix (50)
Neo4j (82)
InfluxDB (0)
Apache CouchDB (44)
Firebird (5)
Database Management (1411)
Databases AllOther (288)