Answer Posted / rajshri.20
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 ? | 1 Yes | 0 No |
Post New Answer View All Answers
Why does for update in oracle 8 cause an ora-01002 error?
How to use in conditions in oracle?
I creat Credit memo in AR. Now i want revers the Credit Memo.how you can revers that what out any aditional entry.
What is raw datatype?
How to shutdown your 10g xe server?
What is difference between truncate and delete?
What are the different types of record groups in oracle? Explain each of them
What is oracle latest version?
Explain the dml?
how can db_files > maxdatafiles since db_files is for instance and the later is for database
Why oracle is used?
What is a data dictionary and how can it be created?
How to use windows user to connect to the server?
How many data types are supported?
How to retrieve the count of updated rows?