What is the structure of a PL SQL block?

What is the structure of a PL SQL block?

PL/SQL is a block-structured language whose code is organized into blocks. A PL/SQL block consists of three sections: declaration, executable, and exception-handling sections. In a block, the executable section is mandatory while the declaration and exception-handling sections are optional.

How functions and procedures are called in a PL SQL block?

Procedures and functions defined within a package are known as packaged subprograms. Procedures and functions nested inside other subprograms or within a PL/SQL block are known as local subprograms, which cannot be referenced by other applications and exist only inside of the enclosing block.

What are the three basic section of a PL SQL block?

As Figure 1-1 shows, a PL/SQL block has three parts: a declarative part, an executable part, and an exception-handling part. (In PL/SQL, a warning or error condition is called an exception.) Only the executable part is required. The order of the parts is logical.

What is PL SQL block in Oracle?

A PL/SQL block is defined by the keywords DECLARE , BEGIN , EXCEPTION , and END . These keywords partition the block into a declarative part, an executable part, and an exception-handling part. Only the executable part is required.

How many sections are there in PL SQL block?

A PL/SQL block has up to four different sections, only one of which is mandatory: Header. Used only for named blocks. The header determines the way the named block or program must be called.

What are the features of PL SQL block?

Features of PL/SQL

• PL/SQL is tightly integrated with SQL.
• It offers extensive error checking.
• It offers numerous data types.
• It offers a variety of programming structures.
• It supports structured programming through functions and procedures.
• It supports object-oriented programming.

What is the difference between procedure and function in Plsql?

Procedures are basic PL SQL blocks to perform a specific action. Functions are blocks used mainly to perform the computations. Functions must return the value. When you are writing functions make sure that you can write the return statement.

What is trigger in Plsql?

A PL/SQL trigger is a named database object that encapsulates and defines a set of actions that are to be performed in response to an insert, update, or delete operation against a table. Triggers are created using the PL/SQL CREATE TRIGGER statement.

What is the difference between SQL and Plsql?

SQL is data oriented language. PL/SQL is application oriented language. SQL is used to write queries, create and execute DDL and DML statments. PL/SQL is used to write program blocks, functions, procedures, triggers and packages.

What are the four main sections of an Oracle PL SQL block structure?

PL/SQL Block Structure

• [DECLARE] Declaration statements; BEGIN Execution statements; [EXCEPTION] Exception handling statements; END; /
• BEGIN NULL; END;
• SET SERVEROUTPUT ON SIZE 1000000 BEGIN DBMS_OUTPUT.PUT_LINE(‘Hello PL/SQL’); END; /

What is the syntax of PL SQL block structure?

PL/SQL Block Syntax Below is the syntax of the PL/SQL block structure. DECLARE –optional BEGIN –mandatory EXCEPTION –optional END; –mandatory /

How do you end a PL/SQL block?

Every PL/SQL statement ends with a semicolon (;). PL/SQL blocks can be nested within other PL/SQL blocks using BEGIN and END. Following is the basic structure of a PL/SQL block − DECLARE message varchar2(20):= ‘Hello, World!’;

Can a PL/SQL file contain SQL code?

This can contain both PL/SQL code and SQL code. This can contain one or many blocks inside it as a nested block. This section starts with the keyword ‘BEGIN’. This section should be followed either by ‘END’ or Exception-Handling section (if present)

Where should the declare Section start in a PL/SQL block?

This should be the first section in a PL/SQL block, if present. This section starts with the keyword ‘DECLARE’ for triggers and anonymous block. For other subprograms, this keyword will not be present.