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PL/SQL is a block structured language because it can have multiple blocks. SQL stands for Structured Query Language i.e. used to perform operations on the records stored in database like inserting data, updating data , deleting data , creating, modifying and dropping tables, views etc.
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PL/SQL a New Way For The Arrangement of Records in Database PL/SQL is a block structured language because it can have multiple blocks. SQL stands for Structured Query Language i.e. used to perform operations on the records stored in database like inserting data, updating data , deleting data , creating, modifying and dropping tables, views etc. What is PL/SQL ? It is a block structured language. The programs of it are logical blocks that can contain any number of nested sub-blocks. PL/SQL stands for "Procedural Language extension of SQL" that is used in Oracle. It is integrated with Oracle database (since version 7). Why Use PL/SQL? An application that uses Oracle Database is worthless unless only correct and complete data is persisted. The time-honored way to ensure this is to expose the database only PL/SQL via an interface that hides the implementation details the tables and the statements that operate on these. This approach is generally called the thick database paradigm, because subprograms inside the database issue the statements from code that implements the surrounding business logic; and because the data can be changed and viewed only through a PL/SQL interface.
This programming language was developed by Oracle Corporation in the late 1980s as procedural extension language and the Oracle relational database. Following are certain facts about PL/SQL - It is a completely portable, high-performance transaction- processing language. It provides a built-in, interpreted and OS independent programming environment. It can also directly be called from the command-line Interface. Features of PL/SQL It has the following features − It 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. It supports the development of web applications and server pages. PL/SQL Program Units A unit is any one of the following −
PL/SQL block Function Package Package body Procedure Trigger Type Type body It is not case sensitive so we are free to use lower case letters or upper case letters except within string and character literals. A line of text contains groups of characters known as lexical units. It can be classified as follows: Delimeters Identifiers Literals Comments PL/SQL Variables A variable is a meaningful name which facilitates a programmer to store data temporarily during the execution of code. It helps us to manipulate data in programs. It is nothing except a name given to a storage area. Each variable in it has a specific data type which defines the size and layout of the variable's memory. A variable should not exceed 30 characters. Its letter optionally followed by more letters, dollar signs, numerals, underscore etc.
Advantages of PL/SQL It has the following advantages − SQL is the standard database language and PL/SQL is strongly integrated with SQL. It supports both static and dynamic SQL. Static supports DML operations and transaction control from PL/SQL block. In Dynamic , it allows embedding DDL statements in blocks. It allows sending an entire block of statements to the database at one time. This reduces network traffic and provides high performance for the applications. It gives high productivity to programmers as it can query, transform, and update data in a database. It saves time on design and debugging by strong features, such as exception handling, encapsulation, data hiding, and object- oriented data types. Applications written in PL/SQL are fully portable. It provides high security level. It provides access to predefined SQL packages. It provides support for Object-Oriented Programming. It provides support for developing Web Applications and Server Pages. Satish Kartan has been working with SQL Server for the past 20 years. He has worked for many years in leading IT Services firms worldwide. He writes on SQL and IT services. For more reading, please visit here: http://satishkartan.strikingly.com/