T-SQL: Deleting all duplicate rows but keeping one

📚Title: T-SQL: Deleting Duplicate Rows with Efficiency and Ease

Are you struggling with eliminating duplicate rows in your T-SQL table without risking the loss of important data? We've got you covered! In this blog post, we'll guide you through the process of efficiently deleting duplicate rows while preserving at least one. Let's dive right in! 💪

🔍Understanding the Problem

So, you've encountered duplicates in your T-SQL table, but you want to keep at least one unique row while removing the redundant ones. Good news: you're not alone! 🙌

⚡️Easy Solutions

To tackle this issue, we'll explore two commonly used methods:

1️⃣ Using ROW_NUMBER():

You can utilize the ROW_NUMBER() function to assign a sequential number to each row, partitioned by the key columns. Then, we can delete all rows except those with a row number of 1.

WITH CTE AS (
  SELECT *,
  ROW_NUMBER() OVER (PARTITION BY key_column1, key_column2 ORDER BY (SELECT NULL)) AS RowNum
  FROM your_table
)

DELETE FROM CTE WHERE RowNum > 1;

2️⃣ Using a Temporary Table:

In this approach, we create a temporary table to store the distinct rows. We then truncate the original table and insert the unique rows back into it.

SELECT DISTINCT *
INTO #temp_table
FROM your_table;

TRUNCATE TABLE your_table;

INSERT INTO your_table
SELECT *
FROM #temp_table;

DROP TABLE #temp_table;

🚀Boost Your SQL Game

While you can now confidently delete duplicate rows efficiently, there's always more to learn to enhance your T-SQL skills! Check out our blog for more exciting tips and tricks. Feel free to share your experiences or ask questions in the comments below. Let's grow together! 👩‍💻👨‍💻

So what are you waiting for? Clean up those duplicates in a snap and make your T-SQL table shine again! 💫

Remember, practice makes perfect, so give these techniques a try and let us know how it went. Don't forget to share this post with your fellow SQL enthusiasts! Sharing is caring, after all. 😊

Happy coding! 💻💡