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

Sequential control - pl/sql, Sequential Control Dissimilar to the IF and ...

Sequential Control Dissimilar to the IF and LOOP statements, the GOTO and NULL statements are not important to the PL/SQL programming. The configuration of PL/SQL is such that th

Records - syntax, Records Records are the items of the type RECORD. The...

Records Records are the items of the type RECORD. The Records have exclusively named fields that can store the data values of various types. And hence, a record treat associate

Calculating a Shopper''s Total Spending, Many of the reports generated from...

Many of the reports generated from the system calculate the total dollars in a shopper''s purchases. Follow these steps to create a function named TOT_PURCH_SF that accepts a shopp

Transaction control, Transaction Control The Oracle is transaction orie...

Transaction Control The Oracle is transaction oriented; that is, Oracle uses the transactions to make sure the data integrity. The transaction is a sequence of SQL data manip

Example of groupby operator - sql, Example of GROUPBY Operator Example...

Example of GROUPBY Operator Example: How many students sat each exam, using GROUP BY, NATURAL LEFT JOIN, and COALESCE SELECT CourseId, COALESCE (n, 0) AS n FROM COURS

When are constraints checked - sql, When Are Constraints Checked Unde...

When Are Constraints Checked Under the model constraints are conceptually checked at all statement boundaries (and only at statement boundaries). By default the same is true

Need database development with analysis tools, Need Database Development wi...

Need Database Development with Analysis Tools Project Description: I want a database for large governmental and private data sets on one country that can be simply extended t

Using set transaction, Using SET TRANSACTION You use the SET TRANSACTI...

Using SET TRANSACTION You use the SET TRANSACTION statement to begin the read-only or read-write transaction, start an isolation level, or assign your present transaction to a

Set operators - sql operators, Set Operators The Set operators combine...

Set Operators The Set operators combine the results of the two queries into one result. The INTERSECT returns all the distinct rows selected by both queries. The MINUS returns

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

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