what is the difference between trigger and constraint?
Answers were Sorted based on User's Feedback
Answer / kumar jabu
Constraints implements specific conduct or rules on table column like it determines whether field data should be unique,not null ..
But triiger implements rules on systems or application event.
whenever dml occurs that implemented rules been fired.
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / naga sindhuri
Triggers not apply for existing rows but constraints can
apply for existing rows.
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / milind chopde
1) Constraints can be used for validation but trigger can be used for complex validation and auditing purpose.
2) Trigger is database object but constraint not.
3) Trigger can be fired on DDL commands but constraints are created or altered using DDL commands.
4) Trigger can be fired on particular event like before/after DML but constraint always check before any data insert or update to table.
| Is This Answer Correct ? | 1 Yes | 0 No |
How many indexes can be created on a table in sql?
What are the types of dbms?
What is sql*loader?
how many sql dml commands are supported by 'mysql'? : Sql dba
Why functions are used in sql?
What's the procedure?
What is cte sql?
what are the t string functions available in tsql? : Transact sql
How do you declare a constant?
How will you select unique values from a list of records?
what is a table called, if it has neither cluster nor non-cluster index? What is it used for? : Sql dba
What is parameter substitution in sql?
Oracle (3259)
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)