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

Effects of null in table literal, Effects of NULL in Table Literal Whe...

Effects of NULL in Table Literal When a VALUES expression appears as the source value for an SQL INSERT statement, the key word NULL can appear as a field value, such that for

%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

produce vertical output format- oracle, Create a Oracle procedure to produ...

Create a Oracle procedure to produce vertical output format when selecting rows from a database table.

Translate the given er schema into sql, Consider the schema for FreeCheckin...

Consider the schema for FreeChecking Bank, that we designed given below. Translate the given ER schema into SQL CREATE TABLE statements (indicating primary key, unique and foreign

Using %rowtype-declarations in sql, Using %ROWTYPE The %ROWTYPE attribut...

Using %ROWTYPE The %ROWTYPE attribute gives a record type which represents a row in a table (or view). The record can store the whole row of data selected from the table or fetc

Package specification, The Package Specification The package specificat...

The Package Specification The package specifications contain the public declarations. The scopes of these declarations are local to your database representation and global to t

Cursor variables, Cursor Variables Similar to a cursor, cursor variable...

Cursor Variables Similar to a cursor, cursor variable points to the current row in the result set of a multi-row query. But, dissimilar a cursor, a cursor variable can be opene

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

Query optimization, 1.( /5 marks) Suppose that a B+-tree index with the sea...

1.( /5 marks) Suppose that a B+-tree index with the search key (dept_name, building) is available on relation department. What would be the best way to handle the following selecti

Natural join - sql, Natural Join - SQL In the absence of NATURAL JOIN...

Natural Join - SQL In the absence of NATURAL JOIN Example has to be replaced by something rather more longwinded, as shown in Example. Example: Joining IS_CALLED and IS_EN

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