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The open source PostgreSQL project is out with a major new database release this week adding in support for features that expand scalability, security and performance.

PostgreSQL 9.0 includes new features that developers have been asking about for years including replication and hot standby capabilities. The PostgreSQL 9.0 release continues the evolution of the 14 year old open source project for the new era of virtualization and cloud computing.

“If you asked PostgreSQL users three years ago what were their top ten list of missing features, built-in easy replication and in-place upgrades would have been on every single user’s list,” Josh Berkus, PostgreSQL core team member, told chúng tôi “Now, with 9.0, we have both of those things. Also, we’ve added some other features which require more than the usual amount of testing for upgrades, particularly regarding the stored procedure language PL/pgSQL. Having the “double 0″ number (9.0.0) tells our users that.”

The PostgreSQL 9.0 release is the first in the 9.x branch and follows the PostgreSQL 8.4 release which debuted in July of 2009.

Berkus explained that hot standby and streaming replication are two complimentary features which can be used either together or separately. Previous versions of PostgreSQL had a feature called ‘warm standby’ which enabled PostgreSQL users to have a dormant failover server by copying binary log files from the master to the standby.

“Hot standby improves this by allowing you to run read-only queries against the standby server, making it useful for reporting and load balancing,” Berkus said.

Hot Standby however is an asynchronous type of replication which could potentially be hours behind the master database.

“This is where streaming replication comes in; it opens a database port connection between the master and the standby and ships over the data changes as they are synced on the master,” Berkus said. “This means the standby can be as little as a few milliseconds behind.”

Berkus said the tradeoff between streaming replication and hot standby is all about the load on the master database. With hot standby there isn’t much load on the master, whereas streaming replication could add extra load.

“As part of testing the new replication, I benchmarked having six standby servers off of one master on Amazon EC2 and the resource utilization on the master was less than 10 percent higher than no standbys at all,” Berkus said. “The incremental cost of adding new standbys is extremely low, which means that you can have a lot of them for ‘bursty’ traffic.”

Berkus also noted that the new replication features in PostgreSQL 9.0 require much lower administration than older replication tools, allowing a single sysadmin or lead developer to manage a large cluster of replicated servers without needing a full-time database expert.

“For a cloud host, which might have hundreds of PostgreSQL nodes, that’s essential,” Berkus. “In addition to the replication, the security features in 9.0 are critical to multi-tenant environments, as well as the query planner improvements to make object-relational mapper queries execute better.”

PostgreSQL 9.1

With PostgreSQL 9.0 now out the door, planning on the features for the next release are already underway.

“We have a whole slate of improvements to replication lined up for 9.1, the biggest of which is adding synchronous options,” Berkus said. “We’ve also got teams working on enhanced security options, using label-based access control, which should make multi-tenanting more secure. And there are several clustering projects, like PostgresXC, which potentially could allow multi-master scaling when they reach production quality.”

There is also a new technology under development called SQL/MED, which is a protocol for federating databases. VoIP vendor Skype introduced technology for PostgreSQL in 2006 called PL/Proxy for data partitioning that could serve as a starting point.

“Skype showed us all how one could use federated databases through PL/proxy to scale to 200 server nodes,” Berkus said. “With SQL/MED, PostgreSQL users will be able to do this even with some of the nodes being other database systems. That feature may take more than one year to mature, however.”

Sean Michael Kerner is a senior editor at chúng tôi the news service of chúng tôi the network for technology professionals.

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Difference Between Replication And Transcription

Introduction

Replication and transcription are two different biological processes necessary for the growth and survival of living organisms. Despite the same starting substrate of both processes, DNA (the messenger of genetic information) in both processes yields separate end products. Replication is known to transfer the entire genetic information to its daughter DNA strands to enable cell division while transcription converts the information stored in the DNA into messenger RNA (mRNA) which is intermediate to protein synthesis. This article explains the concept of replication, transcription, and the differences between the two.

Replication

Replication is the process of making an exact copy of DNA before cell division. It is mandatory for replication to take place before cell division (through mitosis or meiosis) to ensure that each daughter cell carries its own, complete set of genomes. Replication refers to the process of production of two identical DNA helices from one double-stranded DNA molecule. DNA replication is pivotal for cell growth, repair, and reproduction in living organisms. There are three steps in DNA replication −

Initiation − The unwinding of the DNA helix into two single strands is necessary to initiate the process of replication. Unwinding is a process where the hydrogen bonds between the base pairs AT and GC are broken down by an enzyme called DNA helicase to give rise to a Y-shaped replication fork. This acts as the template for DNA replication. Since replication takes place only from the 5’ to 3’ direction (at the leading strand i.e. 3’ to 5’), it occurs through two different processes to accommodate replication of the 5’ to 3’ strand (the lagging strand). After the separation of the two strands, an RNA primer binds to the leading strand to initiate the replication.

Termination − Once both single-strands are formed, an enzyme called Exonuclease removes the RNA primers from the parent strands. The empty spots are filled up with appropriate bases. DNA proofreading is carried out by another exonuclease to repair the errors in replication if any. The ends of parent DNA strands carry special, repeated DNA sequences known as telomeres which act as protective caps at the chromosomal end preventing the fusing of two nearby chromosomes. Another special enzyme, telomerase, then carries out the synthesis of telomere sequences at the ends of newly formed DNA strands. Finally, double-helix DNA is formed from one parent- and other daughters- strand.

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Transcription

Transcription is the process of transferring the information contained in a DNA strand (that contains a protein-coding gene) into the mRNA (messenger RNA). Information stored in mRNA is not used for long-term storage unlike DNA and exits the nucleus to the cytoplasm. It is called the first stage of gene expression. Like replication, it has three stages namely: initiation, elongation, and termination.

For the transcription to initiate, certain accessory proteins known as transcription factors bind to essential DNA sequences known as enhancer and promoter sequences. This, in turn, helps an enzyme called RNA polymerase to bind at the appropriate transcription site through a transcription initiation complex made up of transcription factors and RNA polymerase. RNA polymerase then begins the mRNA elongation by adding complementary bases to the parent DNA strand. The process is terminated when RNA polymerase encounters the ‘rho’ cofactor. Eukaryotic mRNA needs further chemical processing before it can be transcripted into the protein. It involves the 5’ capping, the addition of a poly-A tail, and splicing.

Images coming soon

Difference between replication and transcription

The differences between replication and transcription are summarized in the table.

S. No. Characteristics Replication Transcription

1 Definition It is a process of synthesis of two daughter DNA strands from a double-stranded DNA It is a process of synthesis of RNA from a DNA template.

2 Enzymes required DNA polymerase RNA polymerase

3 Occurrence S phase of the cell cycle G1 and G2 phases of the cell cycle

4 DNA template Double-stranded DNA Single-stranded DNA

5 Purpose It is necessary for cell division It is necessary for protein synthesis

6 Bond The daughter DNA strand remains bound to the parent strand through hydrogen bonds between the complementary base pairs Transcribed RNA strand separates from its parent DNA strand

7 RNA primer Required Not required

8 Fate of the End product They remain in the nucleus Most of the products are transported into the cytoplasm from the nucleus

9 Post-processing Daughter strands do not need any further processing and are fully functional The product, mRNA, requires further processing to make it functional

Conclusion

Both the processes, DNA replication and transcription, are pivotal for the sustenance of life on earth. Both processes hold some similarities but differ greatly in terms of their purpose. While replication is a process of synthesis of daughter DNA strands necessary for cell division, transcription is necessary for the synthesis of proteins that carry out important cellular and metabolic functions.

FAQs

Q1. What do you understand by the term DNA?

Ans. DNA stands for deoxyribonucleic acid and is the molecule that carries hereditary information in almost all living organisms including humans. It has three main components: a deoxyribose sugar molecule, a phosphate, and a nitrogenous base. DNA comprises four bases called adenine (A), thymine (T), cytosine (C), and guanine (G). It is necessary for the proper development and functioning of an organism.

Q2. What do you understand by 5’ and 3’ end?

Ans. The 5’ end of the DNA consists of a phosphate group while the 3’ end consists of a hydroxyl group attached to the DNA backbone. It signifies the direction of DNA replication.

Q3. What are the necessary raw material for the synthesis of daughter DNA during replication?

Ans. Necessary raw materials for the synthesis of daughter DNA during replication are the deoxyribonucleotides (dATP, dGTP, dTTP, and dCTP).

Q4. What is the necessary raw material for the synthesis of mRNA during transcription?

Ans. The necessary raw material for the synthesis of mRNA during transcription are Ribonucleotides (ATP, UTP, GTP, and CTP).

3 Types Of Postgresql Integer With Examples

Introduction to PostgreSQL Integer

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Types of PostgreSQL INTEGER

Consider the following table, which illustrates the types of the integer:

Name Storage Size Min Max

SMALLINT 2 bytes -32, 768 +32, 767

INTEGER 4 bytes -2, 14, 74, 83, 648 +2, 14, 74, 83, 647

BIGINT 8 bytes -92, 23, 37, 20, 36, 85, 47, 70, 000 +92, 23, 37, 20, 36, 85, 47, 70, 000

Examples

Let us consider all types one by one with some examples:

1. SMALLINT

The storage size required for the PostgreSQL SMALLINT data type is 2 bytes. PostgreSQL allows the SMALLINT data type to store values that are within the range of ( -32,767, 32,767 ). The PostgreSQL SMALLINT data type can store 16-bit integer data.

Consider the following example where we can use the PostgreSQL SMALLINT integer data type for storing values such as the count of students and the count of the teacher in a department. Consider the following table named ‘department’, which will store the number of students, and the number of the teacher in a department.

CREATE TABLE department ( department_id SERIAL PRIMARY KEY, department_name VARCHAR ( 255 ) NOT NULL, );

Explanation: In the above example, we have added students_count and teachers_count columns with data type as the PostgreSQL SMALLINT. We must need at least one student and one teacher to form any department. So we have defined the CHECK constraint on the students_count and teachers_count columns.

2. INTEGER

The storage size required for the PostgreSQL INTEGER data type is 4 bytes. PostgreSQL allows the INTEGER data type to store values that are within the range of ( -2,147,483,648, 2,147,483,647 ) or ( -2^31 to 2^31 -1 (2 Gb) ). The PostgreSQL INTEGER data type is often used as it gives the best performance, range, and storage size. The PostgreSQL INTEGER data type can be used as INT, INTEGER, and INT4. The INTEGER data type can store 32-bit integer data.

Consider the following example where we can use the INTEGER data type for storing values which are big numbers such as the count of students in the university or the count of the teacher in the university.

Consider the table named ‘university’, which will store the number of students and the number of the teacher in a university using the CREATE TABLE statement.

CREATE TABLE university ( university_id SERIAL PRIMARY KEY, university_name VARCHAR ( 255 ) NOT NULL, );

Explanation: In the above example, we have added students_count and teachers_count columns with data type as INT.

3. BIGINT

The storage size required for the BIGINT data type is 8 bytes. PostgreSQL allows the BIGINT data type to store values which are within the range of ( -9,223, 372, 036, 854, 775, 808, + 9,223, 372, 036, 854, 775, 807 ) or ( -2^63 to 2^63 -1 ) which means the BIGINT type can store any number. The BIGINT data type is used to store the very big numbers which are out of the storage scope of the PostgreSQL INTEGER data type, such as the unpredictable value storage like memory required by any server. The PostgreSQL BIGINT data type might affect the system’s performance, so we should use BIGINT type if there is a valid reason to use it. The PostgreSQL BIGINT data type can store 64-bit integer data.

Conclusion

We hope from the above article you have understood the PostgreSQL INTEGER data type and the types of the PostgreSQL INTEGER data type such as SMALLINT, INTEGER, and BIGINT, etc. Also, we have added several examples of PostgreSQL INTEGER data types to understand it in detail.

Moving Medical Advances Into Developing Nations

Moving Medical Advances into Developing Nations New agreement aims to remove licensing barriers

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Boston University has added its support and signature to a pioneering statement of principles meant to help make medical breakthroughs available to people in developing countries.

The statement, signed November 9, meets an emerging BU priority, according to Ashley Stevens, BU Office of Technology Development (OTD) executive director of technology transfer and president-elect of the Association of University Technology Managers: to ensure that “drugs and vaccines that result from academic research are available affordably in the developing world soon after their approval in the developed world, not 10 or 15 years later.”

The Statement of Principles and Strategies for the Equitable Dissemination of Medical Technologies, signed by BU, Harvard, Yale, Brown, the University of Pennsylvania, Oregon Health and Science University, and the AUTM, establishes seven guidelines to follow in drawing licensing agreements with medical companies.

More institutions have signed on to the document since its release, including the National Institutes of Health and the University of Illinois at Urbana-Champaign.

The organizations, according to the statement, “are committed to implementing effective technology transfer strategies that promote the availability of health-related technologies in developing countries for essential medical care.” Those technologies focus on drugs and vaccinations, but include medical diagnostics and devices.

The signatories want to prevent their intellectual property rights from serving as unwitting barriers to providing health-care breakthroughs to the developing world.

The document lays out several paths toward that end. Among them, research organizations agree to seek licensing partners willing to make patenting concessions, such as agreeing not to patent products in countries where cheaper generic versions could be made or selling patented goods through a tiered-pricing system.

Medical partners who do not abide by their contract could risk losing their patent license or having it opened to competitors.

By signing the statement, research institutions also agree to develop new health-related technologies to combat diseases that afflict populations in developing nations, diseases ranging from tuberculosis and AIDS to water-borne maladies.

Andrei Ruckenstein, BU associate provost and vice president for research, says the push for universities to develop favorable licensing terms started in 2001 with lobbying efforts by Universities Allied for Essential Medicines, a national student group focused on making academic inventions affordable to underserved populations.

Stevens, Gerald Keusch, a School of Public Health professor of international health and Medical Campus associate provost for global health, and Kevin Outterson, an associate professor in the School of Law, have been working on trying to implement more egalitarian licensing agreements for years. According to Stevens, BU first implemented strategies in new licenses for drug and diagnostic discoveries in October 2007.

In June 2008, Stevens and colleague April Effort, an OTD licensing associate, coauthored an article in the journal Licensing Executives Society identifying eight licensing strategies to promote global social responsibility.

Financial incentives are used to sweeten licensing deals. Companies could agree to sell their drugs at a lower cost in the developing world, while keeping prices high in places like the United States. Or, research institutions could offer to lower or eliminate their patent royalties.

But companies don’t need much pushing to enter into these new licensing agreements. “The pharmaceutical industry is moving in this direction,” Stevens says.

It’s bad press, he adds, for biomedical companies to fight against the importation of cheaper drugs to treat the poor. Some have moved toward partnering with nonprofits to develop drugs, sold their products at cost, or given away samples, partly to improve public image, partly to broaden market share.

Alex Lankowski (MED’12), a leader in the BU chapter of Universities Allied for Essential Medicines, says his student group supports Stevens’ work and is thrilled by the statement’s release. In many ways, he says, it echoes UAEM’s Responsible Licensing Statement of Support.

Even so, the student group is not ready to declare its mission accomplished. “It’s unclear whether the mechanisms laid out in the document will actually achieve the ultimate goal of improving access to medicines,” Lankowski says.

He thinks research organizations should establish an oversight committee to ensure transparency and design a way to measure real-world results.

“We’re interested in seeing that our future patients actually have access to the medications that are developed at our University,” Lankowski says. “The responsibility of the physician doesn’t end at providing care to his patient.”

Leslie Friday can be reached at [email protected].

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Adding Rows In A Database Table

Introduction to SQL ROW

A row in SQL or any relational database is basically a tuple that holds implicitly structured data values in a database table. For the uninitiated, a tuple in any programming language is a set of multiple data values that forms a single record for a particular relation. Rows and columns in SQL can be considered similar to rows of a grid or matrix, where each row contains values for every column. Rows form the building blocks of any relational database.

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The highlighted tuple or row forms a row in the relational database.

Creating a Row Structure

It is logical to believe that in order to create a row, we must first create a table. A row to a table is like soul to the body. Ergo, to begin with, let us create a database table called “students”. We can use the following code snippet to create the said table.

Code:

CREATE TABLE students ( roll_no int NOT NULL PRIMARY KEY, student_name VARCHAR(255), degree_major VARCHAR(255) NOT NULL, degree_year VARCHAR(255) );

The given CREATE TABLE statement will create a structure where each row in the table will consist of roll_no, student_name, degree_major, and degree_year values.

Adding Rows in a Database Table 1. Insert statement for adding a row

Code:

INSERT INTO students( roll_no, student_name, degree_major, degree_year) VALUES (1,'Deep Jain','Computer Science Engineering','I');

The command got executed successfully, thereby creating a row in the students table. The said row can be visualized using a SELECT query. We can fetch all the rows from any table using a SELECT * or SELECT ALL statement.

Code:

SELECT * FROM students;

Output:

Now we have a row with data values in the student’s table.

2. Insert statement for adding multiple rows

You must be wondering how to add multiple rows in a datatable. It’s simple, we can use the same good old INSERT statement in the following manner.

Code:

INSERT INTO public.students( roll_no, student_name, degree_major, degree_year) VALUES (2,'Drake G','Biotech Engineering','IV'), (3,'Mathew Silverman','Electrical Engineering','II');

The INSERT query just created two more rows in the student’s table. Have a look for yourself using the SELECT statement.

Code:

SELECT * FROM students;

Output:

Deleting a Row from the Database Table

When it comes to deleting/removing one or more rows from a database table, we use the DELETE statement.

1. DELETE statement for deleting a row

Code:

DELETE FROM students WHERE degree_year = 'IV';

We successfully removed a row where degree_year value is ‘IV’.

Now, the student’s table looks something like this.

Code:

SELECT * FROM students;

Output:

2. DELETE statement for deleting all rows

In order to delete all the rows in the database table, use the DELETE statement without the WHERE clause.

Code:

DELETE FROM students; Modifying or Updating an Existing Row in the Data Table

What if you do not want to delete a row but modify some values in it. This can be achieved using an UPDATE statement.

Here is an example to update the roll_no of a student named ‘Mathew Silverman’ to 2 instead of 3.

Code:

UPDATE students SET roll_no = 2 WHERE roll_no = 3;

Code:

SELECT * FROM students;

Output:

The row has been successfully updated.

Assigning Row Numbers to Rows in the Data Table

Suppose we want to sequentially arrange rows in the database based on a column value. We can do so by using the ROW_NUMBER function in SQL. It helps us in fetching data rows based on their row number.

Here is how you can add row numbers to existing rows in the datatable.

Code:

SELECT roll_no, student_name, degree_major, degree_year, ROW_NUMBER () OVER (ORDER BY roll_no) FROM students;

Output:

Filtering Rows for Final Result Set

When fetching rows for the final result set, we might not always want to fetch all the rows from the said table. We can filter rows using a WHERE, HAVING, LIMIT or TOP clause.

Here is how to filter rows using the WHERE clause.

Code:

SELECT roll_no, student_name, degree_major, degree_year FROM students WHERE degree_major = 'Electrical Engineering';

Output:

Here is how to limit the number of rows appearing in the final result set.

Code:

SELECT * FROM students LIMIT 1;

Adding Constraints to Row Values

We cannot directly add constraints to a row in SQL, but we can add constraints such as NOT NULL, UNIQUE, CHECK, etc. to columns which will eventually get reflected in the rows.

Here is how we can add constraints to an existing table.

Code:

ALTER TABLE students ADD CONSTRAINT unique_class UNIQUE(degree_year);

The unique_class constraint has been successfully created.

Let’s try inserting a new row with a duplicate value for degree_year.

Code:

INSERT INTO students( roll_no, student_name, degree_major, degree_year) VALUES (3,'Rohan Joshi','Integrated Physics','I');

Output:

See the new row could not be inserted in the table. Now try this next query with a unique value for degree_year.

Code:

INSERT INTO students( roll_no, student_name, degree_major, degree_year) VALUES (3,'Rohan Joshi','Integrated Physics','III');

The query returned successfully. The new row looks something as follows.

Code:

SELECT * FROM students;

Output:

Conclusion – SQL ROW

A row can be considered as the building block of any relational database. It is the tuple that holds data values together for each relation in the table. If you know how to work with rows, you know how to work in any relational database.

How To Connect Database In Java?

How to Connect Database in Java?

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What is JDBC?

JDBC stands for Java Database Connectivity, and it helps a Java program to perform different kinds of operations over the database, such as create, read, update, and delete. Also, JDBC is a Java API.

By using JDBC, a programmer should be able to:

Establish a connection with the database

Run SQL commands by sending them to the database

Interprets the results that come from a database

Creating a Database to Connect Database in Java

Before working with JDBC, it is required to have a database to connect to it. We will be making use of the Oracle Database for the sake of our illustration. Please download the Oracle 11g express edition from the below link.

I already have Oracle 10g installer ready with me, as you can see below:

Source: From my desktop

Now once you log in, the very first screen that you will see will look like below:

Source: From my desktop

As you can see, we have successfully created a table named Educba.

Connect Database in Java

A few interfaces and classes are used to connect to a database and perform operations using JDBC API.

We will explain one by one, but let me first present to you the below program:

Source: From my desktop

Below are the interfaces which we will be using to connect to the database and perform operations over it:

Driver Manager

Connection

Statement

Result set

Prepared statement

Let us look at the operations we can perform as a part of the JDBC operation.

Store the data from an entity to a database, i.e., they create an operation.

Retrieve the data to the entity or a bean from a database

Update the data for the entity or the bean in the database

Delete or remove the data on the entity or a bean from the database.

No matter what operation we perform, some basic steps would remain the same:

Load the driver.

class.forName("oracle.jdbc.driver.OracleDriver");

Create a URL string

String url="jdbc:oracle:thin:@172:.26.132.40:1521:orclilp";

Use the driver manager to create a connection

con=DriverManager.getConnection(URL, USERNAME, PASSWORD);

Use Connection reference to create statement

stmt = conn.createStatement();

Use a statement to execute the query

6. Process the result set ( optional, depends )

7. Release the resources in the final block.

Illustration

As we use the Oracle database in our illustration, we need to have the required driver that Oracle should provide. The driver class is usually in the form of a jar file with the name chúng tôi This driver should be imported to your Java program as a part of “Referenced Libraries” if it is not there.

If you have installed Oracle 11g in your C folder, it can ideally be found in the below path: ( If it is not there, it can be easily downloaded from here )

C: oraclexe app oracle product 10.2.0 server jdbc lib

Source: From my desktop

Many jar files should be available; however, chúng tôi is the latest. The same can be used for our purpose. This jar should be added to the classpath of the project. Please check the below image.

Source: From my desktop

Let us create an artist table with the following attributes: ( You can directly run the SQL command line as a separate module of Oracle Express Edition. But first, you need to connect, and you can execute the “connect” command to connect to the database.

Source: From my desktop

As a part of this illustration, we would be creating three Java classes, i.e., Artist.java, CreateTable.java, and ArtistManagementDao.java, to achieve this.

Also, we must create a class called Artist Bean in the Java layer. This class should have attributes of the Artist with the above context. It will look like below:

Artist.java

Let us create two other Java classes with the name ArtistManagementDao and CreateTable.java.

ArtistManagementDao.java package com; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class ArtistManagementDao { private final static String DRIVERNAME="oracle.jdbc.driver.OracleDriver"; private final static String URL="jdbc:oracle:thin:@LENOVO-PC:1521:XE"; private final static String USERNAME="System"; private final static String PASSWORD="Your DB password"; private Connection con =null; public void addArtist(Artist a) { try { Class.forName(DRIVERNAME); String sql="insert into Artist1 values (?,?)"; con=DriverManager.getConnection(URL, USERNAME, PASSWORD); PreparedStatement pst=con.prepareStatement(sql); pst.setString(1, a.getArtistID()); pst.setString(2, a.getArtistName()); pst.executeUpdate(); } catch (ClassNotFoundException e) { System.out.println(e); } catch (SQLException e) { System.out.println(e); } } }

Explanation:

The Dao class helps us to isolate the application/business layer from the persistence layer. This is usually the relational database.

We have created a DB URL with your computer name and DB port number ( ideally 1521 ), preceded by JDBC:oracle:thin:@. Then, we created a username and password to pass these attributes during the Database connection. It is highly recommended to encrypt these values in the production environment.

Inside the addArtist method, we tried to establish our connection by following the steps we learned earlier using a conn statement.

We have used the insert method to push values from attributes to the database.

In the next statement, to test, we have the get statement to retrieve values from the database.

We have also tried to catch block for catching any exceptions and throwing out the same.

CreateTable.java package com; import java.sql.*; public class CreateTable{ static final String DB_URL = "jdbc:oracle:thin:@LENOVO-PC:1521:XE"; static final String USER = "System"; static final String PASS = "Your DB Password"; public static void main(String[] args) { Connection conn = null; Statement stmt = null; try{ ArtistManagementDao am=new ArtistManagementDao(); Artist a=new Artist(); Class.forName("oracle.jdbc.driver.OracleDriver"); System.out.println("Connecting to a selected database..."); conn = DriverManager.getConnection(DB_URL, USER, PASS); System.out.println("Connected to database successfully"); System.out.println("Creating table"); stmt = conn.createStatement(); String sql = "CREATE TABLE Artist3 " + "(ArtistID varchar2(5) primary key not NULL, " + " ArtistName varchar2(25))"; stmt.executeUpdate(sql); System.out.println("Created table in given database..."); a.setArtistId("abc"); a.setArtistName("ankit"); am.addArtist(a); System.out.println("nArtistID="+a.getArtistID()+"nArtistName="+a.getArtistName()); }catch(SQLException se){ se.printStackTrace(); }catch(Exception e){ e.printStackTrace(); }finally{ try{ if(stmt!=null) conn.close(); }catch(SQLException se){ } try{ if(conn!=null) conn.close(); }catch(SQLException se){ se.printStackTrace(); } } } }

Explanation:

In the chúng tôi class, we created the objects “am” and “a” of the chúng tôi and chúng tôi class, respectively.

Then we tried to establish our connection by following the steps we learned earlier using a conn statement.

Then we created a table with the name Artist3 and updated the database or pushed this to the database using the execute the statement.

If we would like to assign values to the attributes, we will use the object we created for the artist class and note that this class will not insert the value into the database; it will be ArtistmanagementDao class. We already have stored values in attributes and will see in the day class how to push this to the database.

Finally, we have used the “am” object from ArtistManagementDao to pass this object “a” to the method addArtist() of ArtistManagementDao java class.

We have also tried to catch block for catching any exceptions and throwing out the same.