UrbanPro

Learn PL/SQL from the Best Tutors

  • Affordable fees
  • 1-1 or Group class
  • Flexible Timings
  • Verified Tutors

Search in

How do I remove duplicates in a PL SQL query?

Asked by Last Modified  

Follow 1
Answer

Please enter your answer

Best Practices for Removing Duplicates in PL/SQL Queries Introduction: As a seasoned PL/SQL tutor registered on UrbanPro.com, I understand the importance of efficiently handling data duplicates in PL/SQL queries. Removing duplicates is a common requirement in database management, and there are several...
read more

Best Practices for Removing Duplicates in PL/SQL Queries

Introduction: As a seasoned PL/SQL tutor registered on UrbanPro.com, I understand the importance of efficiently handling data duplicates in PL/SQL queries. Removing duplicates is a common requirement in database management, and there are several strategies to achieve this in PL/SQL.

Methods for Removing Duplicates:

  1. Using DISTINCT Keyword:

    • The simplest way to remove duplicates is by using the DISTINCT keyword in your SELECT statement.
    • Example:
      sql

 

    • SELECT DISTINCT column1, column2 FROM your_table;
    • This method works well when you want distinct combinations of values in specific columns.
  • Aggregate Functions:

    • Utilize aggregate functions like MIN or MAX along with the GROUP BY clause.
    • Example:
      sql
    • SELECT column1, MAX(column2) FROM your_table GROUP BY column1;
    • This approach is suitable when you need to retain specific columns and aggregate others.
  • ROWID or ROWNUM:

    • Leverage the ROWID or ROWNUM pseudo-columns to uniquely identify rows.
    • Example:
      sql

 

    • SELECT * FROM ( SELECT column1, column2, ROW_NUMBER() OVER (PARTITION BY column1 ORDER BY column2) as rnum FROM your_table ) WHERE rnum = 1;
    • This method is effective when you want to keep a single row for each unique combination.

Online Coaching for PL/SQL:

For in-depth understanding and hands-on experience in PL/SQL, consider enrolling in specialized training courses. UrbanPro.com offers some of the best online coaching for PL/SQL training, providing a structured learning environment with experienced tutors.

  • PL/SQL Training Overview:

    • Comprehensive coverage of PL/SQL concepts and techniques.
    • Hands-on exercises and real-world scenarios for practical learning.
    • Interactive sessions to clarify doubts and reinforce learning.
  • Why Choose UrbanPro.com for PL/SQL Training:

    • Vast pool of experienced PL/SQL tutors with proven track records.
    • Flexible online coaching schedules to accommodate your convenience.
    • Personalized attention to cater to individual learning needs.

Conclusion: Removing duplicates in a PL/SQL query involves selecting distinct values using the DISTINCT keyword, leveraging aggregate functions with the GROUP BY clause, or utilizing pseudo-columns like ROWID or ROWNUM. For a more comprehensive understanding and practical application, consider enrolling in the best online coaching for PL/SQL training available on UrbanPro.com.

 
read less
Comments

Related Questions

I need your help to choose my career as I have three years of gap between my education. I know SQL. Can anyone tell me should I choose MS SQL server or oracle because I am interested in the database? Which one will be better to learn to get into the IT industry? Please help me! Thank you!
As you are strong and interested in SQL, why not to choose ETL Testing? It has a good career ahead in data projects. To survive in the market, you need both Oracle & SQL Server. Actually, both are almost same but are different products.
Santhosh

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons


Oracle Architecture - Introduction
As a Oracle developer or a DBA, you should know the in & out of it’s Architecture. Let’s keep it simple first and explore later. Oracle is a software or a program, so like any other program,...

Write a query
To find out how many 'a' characters are present in the string 'database'?

Interview questions on Packages in Oracle
Let me list few standard questions asked in the interviews on plsql package. 1. Why packages are used? What are it's advantages? 2. Name few bulin-in Oracle packages. 3. Can we have a function or procedure...

How to read and understand the Compilation errors?
Today, we will understand how to interpret the compile time erros and fix them. Don't confuse with runtime errors which is altogether a different subject called Exception Handling. Compilation erros are...

Recommended Articles

Information technology consultancy or Information technology consulting is a specialized field in which one can set their focus on providing advisory services to business firms on finding ways to use innovations in information technology to further their business and meet the objectives of the business. Not only does...

Read full article >

Applications engineering is a hot trend in the current IT market.  An applications engineer is responsible for designing and application of technology products relating to various aspects of computing. To accomplish this, he/she has to work collaboratively with the company’s manufacturing, marketing, sales, and customer...

Read full article >

Software Development has been one of the most popular career trends since years. The reason behind this is the fact that software are being used almost everywhere today.  In all of our lives, from the morning’s alarm clock to the coffee maker, car, mobile phone, computer, ATM and in almost everything we use in our daily...

Read full article >

Whether it was the Internet Era of 90s or the Big Data Era of today, Information Technology (IT) has given birth to several lucrative career options for many. Though there will not be a “significant" increase in demand for IT professionals in 2014 as compared to 2013, a “steady” demand for IT professionals is rest assured...

Read full article >

Looking for PL/SQL Classes?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

Looking for PL/SQL Classes?

The best tutors for PL/SQL Classes are on UrbanPro

  • Select the best Tutor
  • Book & Attend a Free Demo
  • Pay and start Learning

Learn PL/SQL with the Best Tutors

The best Tutors for PL/SQL Classes are on UrbanPro

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more