Referencing records, PL-SQL Programming

Assignment Help:

Referencing Records

Unlike the elements in a collection, that are accessed using subscripts, the fields in a record are accessed by name. To reference an individual field, you can use the dot notation and the syntax which is as shown:

record_name.field_name

For illustration, you reference field hire_date in record emp_info as shown:

emp_info.hire_date ...

When calling a function which returns a user-defined record, use the syntax below to reference the fields in the record:

function_name(parameter_list).field_name

For illustration, the call to function nth_highest_sal references to the field salary in record emp_info:

DECLARE

TYPE EmpRec IS RECORD (

emp_id NUMBER(4),

job_title CHAR(14),

salary REAL(7,2));

middle_sal REAL;

FUNCTION nth_highest_sal (n INTEGER) RETURN EmpRec IS

emp_info EmpRec;

BEGIN

...

RETURN emp_info; -- return record

END;

BEGIN

middle_sal := nth_highest_sal(10).salary; -- call function

When calling a parameter less function, following syntax can be use:

function_name().field_name -- note empty parameter list

To reference the nested fields in a record returned by a function, use the extended dot notation. The syntax is as shown:

function_name(parameter_list).field_name.nested_field_name

For illustration, the following call to function item references to the nested field minutes in record item_info:

DECLARE

TYPE TimeRec IS RECORD (minutes SMALLINT, hours SMALLINT);

TYPE AgendaItem IS RECORD (

priority INTEGER,

subject VARCHAR2(100),

duration TimeRec);

FUNCTION item (n INTEGER) RETURN AgendaItem IS

item_info AgendaItem;

BEGIN

...

RETURN item_info; -- return record

END;

BEGIN

...

IF item(3).duration.minutes > 30 THEN ... -- call function

END;


Related Discussions:- Referencing records

Map and order methods, Map and Order Methods: The values of the scalar...

Map and Order Methods: The values of the scalar datatype like CHAR or REAL have a predefined order that allows them to be compared. While, the instances of an object type has

Row counterparts of table operators - sql, Row Counterparts of Table Operat...

Row Counterparts of Table Operators SQL does not have counterparts tuple rename, tuple projection, tuple extension, tuple join and tuple compose. To obtain the same effects as

Explicit cursors, Explicit Cursors The set of rows returned by the que...

Explicit Cursors The set of rows returned by the query can include zero, one, or multiple rows, depending on how many rows meet your search criteria. Whenever a query returns

Initializing records, Initializing Records The illustration below show...

Initializing Records The illustration below shows that you can initialize a record in its type definition. Whenever you declare a record of the type TimeRec, its 3 fields supp

Triggers, At times, customers make mistakes in submitting their orders and ...

At times, customers make mistakes in submitting their orders and call to cancel the order. Brewbean’s wants to create a trigger that automatically updates the stock level of all pr

Use bulk binds - improve performance of application, Use Bulk Binds If...

Use Bulk Binds If SQL statements execute inside a loop using the collection elements as bind variables, context switching between the PL/SQL & SQL engines can slow down the ex

Magento change address format depending on store, Magento change address fo...

Magento change address format depending on store Project Description: What I need is that depending on the store in which the customer bought the address should change the fo

Processing transactions, Processing Transactions This part describes ho...

Processing Transactions This part describes how to do the transaction processing. You learn the fundamental techniques that safeguard the consistency of your database, involvin

Oracle, Literature review

Literature review

Scope rules - user-defined exceptions, Scope Rules You cannot declare ...

Scope Rules You cannot declare an exception twice in the similar block. Though, you can, declare the similar exception in 2 different blocks. The Exceptions declared in a bloc

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