Interested to Buy Any Domain ? << Click Here >> for more details...
What do you mean by NOT NULL? When will you use it?
- 3 Answers
- 6342 Views
- I also Faced
- E-Mail Answers
Answer Posted / andank
NOT NULL is the keyword used define columns, when create a
table. When you specify NOT NULL to a column, that column
can not hold NULL values.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
How do I optimize a query in db2?
Where do you specify them?
What is the difference between plan and package in db2?
How can you find out the # of rows updated after an update statement?
What is ibm db2 client?
What is cursor with hold option in db2?
Why db2 is called db2?
How to retrieve rows from a db2 table in embedded sql?
List down the types of triggers in the db2 database?
What is the result of open cursor statement?
How would the varchar column remarks defined?
What is syscat in db2?
Which component is responsible for processing sql statements and selecting access paths?
What is a db2 table?
SET is the ANSI standard for variable assignment, SELECT is not. SET can only assign one variable at a time, SELECT can make multiple assignments at once. If assigning from a query, SET can only assign a scalar value. If the query returns multiple values/rows then SET will raise an error. SELECT will assign one of the values to the variable and hide the fact that multiple values were returned (so you'd likely never know why something was going wrong elsewhere - have fun troubleshooting that one) When assigning from a query if there is no value returned then SET will assign NULL, where SELECT will not make the assignment at all (so the variable will not be changed from it's previous value) As far as speed differences - there are no direct differences between SET and SELECT. However SELECT's ability to make multiple assignments in one shot does give it a slight speed advantage over SET.
