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

Write a program, to write a heap sort program usin pl-sql

to write a heap sort program usin pl-sql

Understanding nested tables, Understanding Nested Tables Within the data...

Understanding Nested Tables Within the database, the nested tables can be considered as one-column database tables. The Oracle stores the rows of a nested table in no specific o

Long and long raw in pl/sql, LONG and LONG RAW You use the LONG datatyp...

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

Effects of null operator, Effects of NULL Operator As a general rule-b...

Effects of NULL Operator As a general rule-but not a universal one-if NULL is an argument to an invocation of a system-defined read-only operator, then NULL is the result of t

Advantages of exceptions, Advantages of Exceptions Using the exception...

Advantages of Exceptions Using the exceptions for the error handling has many benefits. Without an exception handling, every time you issue a command, you should ensure for th

Updating objects in pl sql, Updating Objects: To change the attributes...

Updating Objects: To change the attributes of objects in an object table, you can use the UPDATE statement, as the illustration below shows: BEGIN UPDATE persons p SET p

Cosmozoic theory - origin of life, COSMOZOI C THEORY - Richter (1865...

COSMOZOI C THEORY - Richter (1865) proposed the cosmozoic theory that says that life came by spores (cosmozoa) or other particles from other planets on the earth.

Between and not between operator in sql, BETWEEN and NOT BETWEEN Operator i...

BETWEEN and NOT BETWEEN Operator in SQL Example: Restricting exam marks to between 0 and 100 CREATE ASSERTION Marks_between_0_and_100 CHECK (NOT EXISTS (SELECT * FROM

Object type in pl/sql, Object Type: The object type is a user-define...

Object Type: The object type is a user-defined composite datatype which encapsulates a data structure along with the functions and procedures required to manipulate the data

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

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