Defining records, PL-SQL Programming

Assignment Help:

Defining and Declaring Records

To create records, you have to define a RECORD type, and then declare records of that type. You may also define RECORD types in the declarative part of any PL/SQL subprogram, block,  or package using the syntax as shown:

TYPE type_name IS RECORD (field_declaration[,field_declaration]...);

where field_declaration stands for

field_name field_type [[NOT NULL] {:= | DEFAULT} expression]

And where the type_name is a type specifier used later to declare the records, field_ type is any PL/SQL datatype except REF CURSOR, and expression yields a value of the similar type as the field_type.

Note:  Unlike the TABLE and VARRAY types, the RECORD types cannot be CREATED and stored in the database.

You can use %TYPE & %ROWTYPE to state the field types. In the illustration shown below, you define a RECORD type named DeptRec:

DECLARE

TYPE DeptRec IS RECORD (

dept_id dept.deptno%TYPE,

dept_name VARCHAR2(15),

dept_loc VARCHAR2(15));

Notice that the field declarations are just like the variable declarations. Each field has an exclusive name and specific datatype. Therefore, the value of a record is actually a collection of values, each of some of the simpler type.

As the illustration below shows, the PL/SQL defines records that contain collections, objects, and other records (known as the nested records). Though, the object types cannot have attributes of type RECORD.

DECLARE

TYPE TimeRec IS RECORD (

seconds SMALLINT,

minutes SMALLINT,

hours SMALLINT);

TYPE FlightRec IS RECORD (

flight_no INTEGER,

plane_id VARCHAR2(10),

captain Employee, -- declare object

passengers PassengerList, -- declare varray

depart_time TimeRec, -- declare nested record

airport_code VARCHAR2(10));

The illustration later shows that you can specify a RECORD type in the RETURN clause of a function specification. That permits the function to return a user-defined record of the same type.

DECLARE

TYPE EmpRec IS RECORD (

emp_id INTEGER

last_name VARCHAR2(15),

dept_num INTEGER(2),

job_title VARCHAR2(15),

salary REAL(7,2));

...

FUNCTION nth_highest_salary (n INTEGER) RETURN EmpRec IS...


Related Discussions:- Defining records

Perform exception handling with user-defined errors, On occasion, some of B...

On occasion, some of Brewbean's customers mistakenly leave an item out of a basket already checked out, so they create a new basket containing the missing items. However, they requ

Rollback behavior - bulk bind performance improvement, Rollback Behavior ...

Rollback Behavior When a FORALL statement fails, the database changes are rolled back to an implicit savepoint marked before each of the SQL statement execution. The Changes t

Implement a new discount for return shoppers, Brewbean's is implementing a ...

Brewbean's is implementing a new discount for return shoppers - every fifth completed order receives a 10% discount. The count of orders for a shopper is placed in a packaged varia

Write a pl-sql program using the implicit cursor, Question: a) Given th...

Question: a) Given the following relation: Location(loc_id, bldg_code, room, capacity) The underlined field is a primary key. (i) Write a PL/SQL program using the impl

Pl/sql expressions , Pl/SQL Expressions The Expressions are constructed...

Pl/SQL Expressions The Expressions are constructed by using the operands and operators. An operand is a constant, literal, variable, or function call which contributes a value

Mysql developer/programmer, Project Description: I want somebody who can...

Project Description: I want somebody who can help me with an idea that I have been working on for a few months now. The person will require extensive knowledge of warcraft 3 PvP

Expressions - syntax, Expressions   An expression is a randomly comple...

Expressions   An expression is a randomly complex combination of the constants, variables, literals, operators, & function calls. The simplest expression is the single variabl

Pl/sql conditional control: if statements, Pl/sql Conditional Control: IF s...

Pl/sql Conditional Control: IF statements Frequently, it is necessary to take the alternative actions depending on the circumstances. The IF statement execute a series of statem

Use triggers to maintain referential integrity, At times, Brewbean's has ch...

At times, Brewbean's has changed the id number for existing products. In the past, they have had to add a new product row with the new id to the BB_PRODUCT table, modify all the co

Scope and visibility- pl/sql, Scope and Visibility The References to an ...

Scope and Visibility The References to an identifier are resolved according to its visibility and scope. The scope of an identifier is that area of a program unit (subprogram, b

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