Interested to Buy Any Domain ? << Click Here >> for more details...
What are various constraints used in SQL?
- 1 Answers
- 3938 Views
- Polaris, I also Faced
- E-Mail Answers
SQL constraints are used to specify rules for the data in a table.
NOT NULL - Indicates that a column cannot store NULL value
UNIQUE - Ensures that each row for a column must have a unique value
PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Ensures that a column (or combination of two or more columns) have an unique identity which helps to find a particular record in a table more easily and quickly
FOREIGN KEY - Ensure the referential integrity of the data in one table to match values in another table
CHECK - Ensures that the value in a column meets a specific condition
DEFAULT - Specifies a default value when specified none for this column
| Is This Answer Correct ? | 2 Yes | 0 No |
How you open and close a cursor variable.Why it is required?
What are the different editions of oracle?
What is a sub query? Describe its types?
What is a Data Dictionary ?
What are the components of Physical database structure of Oracle Database?
How to define a variable of a specific record type?
26. Display the earliest shipping date in the format: DD/MON/YYYY
How to execute a stored program unit?
What is the difference between hot backup and cold backup in oracle? Tell about their benefits also.
What is oracle update statement with inner join ?
How to lock and unlock a user account in oracle?
Difference between sub query and nested query ?
19 Answers Keane India Ltd, TCS,
Oracle General 
