Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Avoid the NOT NULL Constraint
In the PL/SQL, using the NOT NULL constraint incur a performance cost. Consider the illustration as shown below:
PROCEDURE calc_m IS
m NUMBER NOT NULL;
a NUMBER;
b NUMBER;
BEGIN
...
m := a + b;
As m is constrained by the NOT NULL, the value of the expression a + b is assigned to a temporary variable, that is then tested for the nullity. If the variable is not null, its value is assigned to m. Or else, an exception is raised. Though, if m were not constrained, then the value would be assigned to m directly. A more accurate way to write the last illustration shown below:
m NUMBER; -- no constraint
IF m IS NULL THEN ... -- enforce constraint programmatically
END;
Multiple Assignment- SQL SQL supports multiple assignment to local variables and also applies multiple assignment semantics in SET clauses of UPDATE statements, but does not
LONG and LONG RAW You use the LONG datatype to store the variable-length character strings. The LONG datatype is such as the VARCHAR2 datatype, except that the maximum length o
Updating by insertion Syntax : INSERT INTO ENROLMENT VALUES (SID ('S4'), 'Devinder', CID ('C1'));
Boolean Values Only the values TRUE, FALSE, & NULL can be assigned to a Boolean variable. For illustration, given the declaration DECLARE done BOOLEAN; the following statements
Cursor Variables: To execute the multi-row query, the Oracle opens an unnamed work region that stores the processing information. You can use an explicit cursor that names
Define basic operators of relational algebra with an example each
Positional Notation The first procedure call uses the positional notation. The PL/SQL compiler relates the first actual parameter, account, with the first proper parameter, ac
Using the FORALL Statement The keyword FORALL instruct the PL/SQL engine to bulk-bind input collections before sending them all to the SQL engine. Though the FORALL statement
Joining in SQL Joining IS_CALLED and IS_ENROLLED_ON in SQL SELECT * FROM IS_CALLED NATURAL JOIN IS_ENROLLED_ON This is an example of an SQL table expression. I have been
Opening a Cursor Opening the cursor executes the query & identifies the result set that consists of all rows that meet the query search criteria. For the cursors declared usin
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd