Cursor variables in pl sql, PL-SQL Programming

Assignment Help:

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 the work region, to access the information. Or, you can use the cursor variable that points to the work region. While a cursor always refers to similar query work region, a cursor variable can refer to various work regions. To create the cursor variables, you can define a REF CURSOR type, and then declare the cursor variables of that type.

The Cursor variables are such as C or Pascal pointers that hold the memory location (address) of a little item rather of the item itself. Therefore, declaring a cursor variable build a pointer, not an item.

1597_constant variable.png

Keyword and Parameter Description:

type_name:

This is a user-defined type specifier that is used in the subsequent declarations of the PL/SQL cursor variables.

REF CURSOR:

In PL/SQL, the pointers have datatype REF X, where REF is short form of REFERENCE and

X stands for the class of objects. And hence, the cursor variables have datatype REF CURSOR.

RETURN:

This keyword introduces the RETURN clause that specifies the datatype of the cursor variable result value. You can use the %ROWTYPE attribute in the RETURN clause to give a record type which presents a row in a database table or a row returned by a cursor or strongly typed cursor variable. You can also use the %TYPE attribute to give the datatype of a earlier declared record.

cursor_name:

These identify an explicit cursor earlier declared within the present scope.

cursor_variable_name:

These identify a PL/SQL cursor variable formerly declared within the present scope.

record_name:

These identify a user-defined record formerly declared within the present scope.

record_type_name:

These identify a RECORD type formerly defined within the present scope.

db_table_name:

These identify a database table (or view) that shuld be accessible when the declaration is elaborated.

%ROWTYPE:

These attributes provides a record type that presents a row in the database table or a row fetched from the cursor or strongly typed cursor variable. The Fields in the record and equivalent columns in the row have similar names and datatypes.

%TYPE:

These attributes provides the datatype of a formerly declared user-defined record.

 


Related Discussions:- Cursor variables in pl sql

Exit-when - iterative control, EXIT-WHEN The EXIT-WHEN statement permits...

EXIT-WHEN The EXIT-WHEN statement permits a loop to complete conditionally. Whenever the EXIT statement is encountered, the condition in the WHEN clause is computed. When the co

Data abstraction, Data Abstraction The Data abstraction extracts the im...

Data Abstraction The Data abstraction extracts the important properties of data while ignoring the not necessary details. Once you design a data structure, you can fail to reme

Fetching with a cursor, Fetching with a Cursor The FETCH statements re...

Fetching with a Cursor The FETCH statements retrieve the rows in the result set one at a time. After each and every fetch, the cursor advance to the next row in the result set

Control structure, Control Structures The Control structures are the mo...

Control Structures The Control structures are the most important PL/SQL extension to the SQL. Not only does PL/SQL let you manipulate Oracle data, it lets you process the data

Declaring cursor variables, Declaring Cursor Variables Once a REF CURS...

Declaring Cursor Variables Once a REF CURSOR type is define by you, and then you can declare the cursor variables of that type in any PL/SQL block or subprogram. In the exampl

Positional notation, Positional Notation The first procedure call uses...

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

Dynamic sql - pl sql, Dynamic SQL: The Most PL/SQL programs do a predi...

Dynamic SQL: The Most PL/SQL programs do a predictable, specific job. For illustration, a stored procedure may accept an employee number and salary increase, and then update t

Multiple assignment - sql, Multiple Assignment- SQL SQL supports mult...

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

Solve the business problems using sql, Use the MASCOT tables CREDITRS, PORD...

Use the MASCOT tables CREDITRS, PORDS and PAYMENTS to write SQL queries to solve the following business problems. These tables / data are available to you via the USQ Oracle server

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