What are the advantages of PL SQL over SQL?
What Are The Advantages Of PL/SQL Over SQL?
- Exceptions can be handled in PL/SQL where as in SQL you cannot.
- PL/SQL uses packages of functions and procedures which are simply stored in the database. And these can be used far more easily.
- Once these functions and procedures (in PL/SQL) are created, they can used anytime in the application. ...
- Batch updates possible in PL/SQL.
What are triggers in PL SQL?
PL/SQL triggers are block structures or pre-defined programs, which may be in-built or even explicitly developed by the programmers for a particular task. Triggers are automatically executed when an event occurs which is well thought of by the programmer in advance.
What are the basic SQL statements?
What are the basic SQL data statements? SELECT – extracts data from a database.UPDATE – updates data in a database.DELETE – deletes data from a database.INSERT INTO – inserts new data into a database.CREATE DATABASE – creates a new database.ALTER DATABASE – modifies a database.CREATE TABLE – creates a new table.
What is PL SQL programming?
What is PL/SQL?
- Structured programming through functions.
- Procedures and object-oriented programming.
- Development of web applications and server pages.
What is PL SQL in simple words?
PL/SQL (Procedural Language for SQL) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 6 - stored PL/SQL procedures/functions/packages/triggers since version 7), Times Ten in-memory database (since version 11.2.
What are the types of PL SQL statements?
PL/SQL has three categories of control statements: conditional selection statements, loop statements and sequential control statements. PL/SQL categories of control statements are: Conditional selection statements, which run different statements for different data values.
What is PL SQL with example?
PL/SQL IntroductionSQLPL/SQLIt is declarative, that defines what needs to be done, rather than how things need to be done.PL/SQL is procedural that defines how the things needs to be done.Execute as a single statement.Execute as a whole block.Mainly used to manipulate data.Mainly used to create an application.2 more rows•Apr 3, 2018
What are the 5 SQL statement types?
Data Definition Language (DDL) Statements. Data Manipulation Language (DML) Statements. Transaction Control Statements. Session Control Statements.
What are the three PL SQL block types?
A PL/SQL block consists of three sections: declaration, executable, and exception-handling sections.
What are the main four variable types used in PL SQL?
PL/SQL uses the SQL character data types such as CHAR , VARCHAR2 , LONG , RAW , LONG RAW , ROWID , and UROWID . CHAR(n) is a fixed-length character type whose length is from 1 to 32,767 bytes. VARCHAR2(n) is varying length character data from 1 to 32,767 bytes.
What are the parts of PL SQL?
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 are types in Oracle?
Oracle object types are user-defined types that make it possible to model real-world entities, such as customers and purchase orders, as objects in the database. New object types can be created from any built-in database types and any previously created object types, object references, and collection types.
Why should we use PL/SQL?
Although PL/SQL at the end executes and processes the SQL statements but consider a scenario of updating the salary record with the hike of 20% of all employees in the Employee table having 1000+ values, is it practical to write the update command 1000+ times and fire SQL query each time to update the records? For this, it came into the picture as though it looping; it can be done in 2 lines of code without any interruption in between
What is the beginning of a PL/SQL block?
It contains all the logic written and tasks that need to be performed using the SQL queries through DDL and DML statements. It starts with the BEGIN keyword and ends with END.
What is a database server?
Database Server. It is the component where the data is stored, and the SQL queries are sent by the PL/SQL Engine to interact with the data. It consists of an SQL executor that parses and process further the SQL.
What is the PL/SQL engine?
This Engine is responsible for the actual processing of the PL/SQL statement. It compiles the code into bytecode and executes it. It separates the PL/SQL and SQL code and sends the actual SQL code to the database server, where it interacts with the database. The PL/SQL engine handles the remaining code.
What is the input part of a database?
It is the main part that contains all the code. The actual input contains the SQL statements and the instructions that will interact with the database.
How many copies of a subprogram are stored in a database?
It is easy to maintain the subprogram as only one copy is stored in the database server, which can be accessed by all the clients and applications using it.
Why are companies ready to give great packages to DBAs?
Companies are ready to give great packages to DBAs as security and maintainability of data is their foremost priority.
Why does Oracle use PL/SQL?
In addition, Oracle also encourages you to use PL/SQL to work with Oracle databases because PL/SQL brings many advantages.
What is PL/SQL 6.0?
Oracle introduced PL/SQL (version 1.0) in its Oracle Database product version 6.0 as the scripting language in SQL*Plus and programming language in SQL*Forms 3.
Why is it so hard to write an application using SQL?
It is difficult to write applications using SQL only because each SQL statement runs independently and has little or no effect on the other. To overcome this limitation, you often have to use other programming languages such as C /C++, Perl, PHP, and Java, by using standard database interfaces. Oracle supports this approach when you want to develop applications that interact with Oracle databases.
Why is Oracle adding enhancements to PL/SQL?
Oracle adds many enhancements to the PL/SQL to make it more efficient to interact with Oracle databases.
Where are PL/SQL programs stored?
PL/SQL programs such as functions and procedures are stored in the Oracle database in compiled form. This allows applications or users to share the same functionality stored in the Oracle database.
Can you move a PL/SQL program to another database?
Once you develop a PL/SQL program in an Oracle Database, you can move it to the other Ora cle Databases without changes , with the assumption that the versions of Oracle database are compatible.
Is PL/SQL a structured language?
PL/SQL is a highly structured language. PL/SQL provides a very expressive syntax that makes it easy for anyone who wants to learn PL/SQL. If you are programming in other languages, you can get familiar with PL/SQL very quickly and understand the intent of the code without difficulty.
What is PL/SQL programming?
PL/SQL is basically a procedural language, which provides the functionality of decision making, iteration and many more features of procedural programming languages. PL/SQL can execute a number of queries in one block using single command.
What is PL/SQL in Oracle?
PL/SQL is a block structured language that enables developers to combine the power of SQL with procedural statements.All the statements of a block are passed to oracle engine all at once which increases processing speed and decreases the traffic.
What is var1 in SQL?
var1 INTEGER : It is the declaration of variable, named var1 which is of integer type. There are many other data types that can be used like float, int, real, smallint, long etc. It also supports variables used in SQL as well like NUMBER (prec, scale), varchar, varchar2 etc.
What is a SQL query?
SQL is a single query that is used to perform DML and DDL operations. It is declarative, that defines what needs to be done, rather than how things need to be done. PL/SQL is procedural that defines how the things needs to be done. Execute as a single statement. Execute as a whole block.
What is the declaration section in SQL?
Declare section starts with DECLARE keyword in which variables, constants, records as cursors can be declared which stores data temporarily. It basically consists definition of PL/SQL identifiers. This part of the code is optional.
What are PL/SQL identifiers?
PL/SQL identifiers. There are several PL/SQL identifiers such as variables, constants, procedures, cursors, triggers etc. Like several other programming languages, variables in PL/SQL must be declared prior to its use. They should have a valid name and data type as well.
What is multi line comment?
Multi Line Comment: To create comments that span over several lines, the symbol /* and */ is used.
What does a searched case statement do?
The searched CASE statement runs the first statements for which condition is true. Remaining conditions are not evaluated. If no condition is true, the CASE statement runs else_statements if they exist and raises the predefined exception CASE_NOT_FOUND otherwise. (For complete syntax, see "CASE Statement" .)
How many times does the for loop statement execute?
In Example 4-25, the FOR LOOP statement executes 10 times unless the FETCH statement inside it fails to return a row, in which case it ends immediately.
Is GOTO a PL/SQL statement?
Unlike the IF and LOOP statements, the sequential control statements GOTO and NULL are not crucial to PL/SQL programming .
What is PL/SQL in Oracle?
What Is PL/SQL. PL/SQL is a fusion of SQL with procedural traits of programming languages. It was launched by Oracle to upgrade the features of SQL. PL SQL is considered as one of the important languages inside the Oracle database. It is primarily an extension of SQL.
What is a PL SQL identifier?
PL SQL identifiers include variables, constants, procedures, cursors, and so on. Their length should not be more than thirty characters and is case insensitive. A keyword in PLSQL cannot be used as an identifier.
What is the difference between SQL and PL/SQL?
Answer: The primary difference between SQL and PL/SQL is that SQL runs only a query at a time but PL/SQL processes a block of code at a time. SQL is known as Structured Query Language and PL/SQL is known as Procedural Language/Structured Query Language.
What is procedural language?
It is known as Procedural Language extensions to the Structured Query Language.
What is a PLSQL comment?
PLSQL code includes comments that explain the intent of the code. PL/SQL has both multiple lines and single-line comments. The single-line comments begin with delimiter double hyphen — and double line comments start with /* and end with */.
What is a block in PLSQL?
Answer: Each statement in PLSQL is known as blocks . Thus a block includes constants, control statements, error checks, SQL queries, variables, and so on.
How to connect to SQL Developer?
In the SQL developer application, click on New Connection from the top left of the screen. Enter the necessary information as provided during the installation process and click on the Connect button.
What is PL/SQL in SQL?
PL/SQL provides the different queries, or we can say commands to the user. Basically, PL/SQL is similar to the SQL language. But PL/SQL introduces the different methods that consist of the block structure, and it is helpful for well suitable development. PL/SQL also provides the variable in which we can perform the variable deceleration as well as we can assign the name as well. PL/SQL structure divides into different sections, and we can write the different queries into an execution section as per user requirement. We can perform the update, create, insert and delete, etc., as per requirement.
What is the second query in PL/SQL?
This is the second query, or we can say that command in PL/SQL. By using this command, we can insert the different records into the specified table that we want. When we need to insert the records into the table, we must require the table name, column name, and values for a column.
What are the arithmetic operators in PL/SQL?
Normally all arithmetic operators are supported to the PL/SQL, such as addition, subtraction, multiplication, and divide.
Does PL/SQL delete records?
PL/SQL also provides the delete query to the user, in which we can easily delete the particular records from the specified table by providing the where clause as per our requirement.
What is the syntax of PL/SQL?
In this chapter, we will discuss the Basic Syntax of PL/SQL which is a block-structured language; this means that the PL/SQL programs are divided and written in logical blocks of code. Each block consists of three sub-parts −
What does a PL/SQL end with?
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 −
What is the optional section of a SQL program?
It is an optional section and defines all variables, cursors, subprograms, and other elements to be used in the program. 2. Executable Commands. This section is enclosed between the keywords BEGIN and END and it is a mandatory section. It consists of the executable PL/SQL statements of the program.
What does the end line mean in SQL?
The end; line signals the end of the PL/SQL block. To run the code from the SQL command line, you may need to type / at the beginning of the first blank line after the last line of the code. When the above code is executed at the SQL prompt, it produces the following result −
What are PL/SQL identifiers?
PL/SQL identifiers are constants, variables, exceptions, procedures, cursors, and reserved words. The identifiers consist of a letter optionally followed by more letters, numerals, dollar signs, underscores, and number signs and should not exceed 30 characters.
Does PL/SQL support single line?
All characters available inside any comment are ignored by the PL/SQL compiler. The PL/SQL single-line comments start with the delimiter -- ( double hyphen) and multi-line comments are enclosed by /* and * /.
What does PL/SQL stand for?
PL/SQL stands for “Procedural language extensions to SQL.”. PL/SQL is a database-oriented programming language that extends SQL with procedural capabilities. It was developed by Oracle Corporation within the early 90’s to boost the capabilities of SQL.
Why use PL/SQL?
PL/SQL is most helpful to put in writing triggers and keep procedures. Stored procedures square measure units of procedural code keep during a compiled type inside the info. Advantages of PL/SQL are as following below: Block structures: It consists of blocks of code, which can be nested within each other.
What are the advantages of SQL?
The advantages of SQL are: SQL could be a high level language that has a larger degree of abstraction than procedural languages. It enables the systems personnel end-users to deal with a number of database management systems where it is available. Portability.
What is the difference between SQL and PLSQL?
Difference between SQL and PLSQL. Structured Query Language (SQL) is a standard Database language which is used to create, maintain and retrieve the relational database. The advantages of SQL are: SQL could be a high level language that has a larger degree of abstraction than procedural languages.
What does SQL specify?
SQL specifies what’s needed and not however it ought to be done.
Does PL/SQL reduce network traffic?
Better performance: PL/SQL engine processes multiple SQL statements at the same time as one block, thereby reducing network traffic.
Is SQL a procedural language?
SQL is declarative language. PLSQL is procedural language. SQL can be embedded in PLSQL. PLSQL can’t be embedded in SQL. It directly interacts with the database server. It does not interacts directly with the database server. It is Data oriented language. It is application oriented language.
PL/SQL
- PL/SQL is an extension of SQL that allows developers to combine the power of SQL with procedural statements. Oracle Corporation developed it in the early ’90s. It allows writing a piece of code, in...
- It is a high standard and readable language, so it is very easy to understand and learn. It can only be used with Oracle Database Systems and cannot be used as a standalone application …
- PL/SQL is an extension of SQL that allows developers to combine the power of SQL with procedural statements. Oracle Corporation developed it in the early ’90s. It allows writing a piece of code, in...
- It is a high standard and readable language, so it is very easy to understand and learn. It can only be used with Oracle Database Systems and cannot be used as a standalone application like C, C++,...
- Before this, only one query is sent to the Oracle server, which increases the load and time. But through this, multiple SQL statements are grouped and sent in a single block or subprogram, which in...
Why Should We Use PL/SQL?
- Although PL/SQL at the end executes and processes the SQL statements but consider a scenario of updating the salary record with the hike of 20% of all employees in the Employee table having 1000+ v...
- Moreover, it is fundamental for any web application to hide the implementation logic from the end-users. It is done through Interfaces in programming languages like Java, C++. Similarly, t…
- Although PL/SQL at the end executes and processes the SQL statements but consider a scenario of updating the salary record with the hike of 20% of all employees in the Employee table having 1000+ v...
- Moreover, it is fundamental for any web application to hide the implementation logic from the end-users. It is done through Interfaces in programming languages like Java, C++. Similarly, the databa...
- All these modules are hidden behind the PL/SQL interface. This way, it maintains the correctness, maintainability, security, and abstraction for both the developers and end-users.
- It provides a special facility to work with the triggers (Triggers are special events that are fired when any specific mentioned situation is met). This deals with various triggers like View level...
Advantages of PL/SQL
- Below given are some of the advantages: 1. It allows the users/developers to run multiple SQL statements at once by wrapping them in a block. 2. It is compatible with SQL. It allows us to use all the SQL statements, data manipulation, cursor handling, transaction statements in PL/SQL blocks. There is no need for conversion between the two of them. 3. It is easy to maintain the su…
How Will This Technology Help You in Career Growth?
- If we talk about any web application, 98% of the application deals with the data, either handling it, storing and manipulating it. To organize and handle huge amounts of data, there is a high deman...
- As for the big applications, all the code cannot be kept in the application layer because it can degrade the overall performance of the application when it comes to sending a large number …
- If we talk about any web application, 98% of the application deals with the data, either handling it, storing and manipulating it. To organize and handle huge amounts of data, there is a high deman...
- As for the big applications, all the code cannot be kept in the application layer because it can degrade the overall performance of the application when it comes to sending a large number of reques...
- Companies are ready to give great packages to DBAs as security and maintainability of data is their foremost priority.
Conclusion
- The above discussion clearly shows the importance and the use of PL/SQL language in the field of database development and so on the application. It can help to deal with the data of the database, but It helps to fire that SQL in a procedural way. So if one needs to dive deep into the field of the database, good knowledge of the language is mandatory.
Recommended Articles
- This has been a guide to What is PL/SQL?. Here we have discuss why should we use it, how this technology will help you in career growth, the advantages, and the Architecture, respectively. You can also go through our other suggested articles to learn more – 1. PL/SQL Commands 2. PL SQL Training 3. Oracle PL/SQL Interview Questions 4. Careers in PL/SQL