Using %type-declarations in sql, PL-SQL Programming

Assignment Help:

Using %TYPE

The %TYPE attribute gives the datatype of a variable or the database column. In the example below, the %TYPE gives the datatype of a variable:

credit REAL(7,2);
debit credit%TYPE;

The Variables declared using %TYPE is treated such as those declared using a datatype specifier. For example, given the earlier declarations, the PL/SQL treats debit such as REAL (7, 2) variable. The later example shows that a %TYPE declaration can involve an initialization clause:

balance NUMBER(7,2);
minimum_balance balance%TYPE := 10.00;
The %TYPE attribute is mainly useful when declaring a variable which refer to a database columns. You can reference a table & column, or you can reference an owner, column, table, and as in

my_dname scott.dept.dname%TYPE;

Using the %TYPE to declare my_dname has two merits. Firstly, you do not require knowing the exact datatype of dname. Secondly, when the database definition of the dname changes, the datatype of my_dname change accordingly at the run time.


Related Discussions:- Using %type-declarations in sql

Defining and declaring collections, Defining and Declaring Collections T...

Defining and Declaring Collections To create the collections, you must define a collection type, and then declare the collections of that type. You can define the VARRAY types a

Anatomy of a command, Anatomy of a Command Figure, showing a simple S...

Anatomy of a Command Figure, showing a simple SQL command, is almost identical to its counterpart in the theory book. The only difference arises from the fact that SQL uses a

Rephrase conditional control statements, Rephrase Conditional Control State...

Rephrase Conditional Control Statements When computing a logical expression, the PL/SQL uses short-circuit evaluation. That is, the PL/SQL stops evaluating the expression as s

Commit statement in pl sql, COMMIT Statement The COMMIT statement expli...

COMMIT Statement The COMMIT statement explicitly makes everlasting changes to the database during the present transaction. The Changes made to the database are not considered e

Avoid the not null constraint - performance of application, Avoid the NOT N...

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 NUMB

Transaction visibility, Transaction Visibility As the figure shows, th...

Transaction Visibility As the figure shows, the changes made by an autonomous transaction become visible to another transaction whenever the autonomous transaction commits. Th

Data type conversion, Datatype Conversion At times it is necessary to c...

Datatype Conversion At times it is necessary to convert a value from one datatype to another. For e.g. if you want to inspect a rowid, you should convert it to a character stri

Triffic light control system, write the program for traffic control system ...

write the program for traffic control system with 10 second, 15 secod, and 20 second delay

%type attribute - syntax, %TYPE Attribute The %TYPE attribute gives the...

%TYPE Attribute The %TYPE attribute gives the datatype of a record, field, nested table, database column, or the variable. You can use the %TYPE attribute as the datatype speci

Sql operators, SQL Operators The PL/SQL uses all the SQL set, compariso...

SQL Operators The PL/SQL uses all the SQL set, comparison, and row operators in the SQL statements. This part briefly describes some of these operators.  1. Comparison Opera

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd