You can use the DISTINCT in SQL Server to get the distinct records only. Apart from this you can also use the ROW_NUMBER (Transact-SQL) function to get the distinct result by assigning the numbers to a result set.

Avoid showing SQL duplicates with our practical, insightful guidebook. Maintain data uniqueness for accurate analysis and reporting.

Dec 6, 2023 · The most common way to remove duplicate rows from our query results is to use the DISTINCT clause. The simplest way to use this is with the DISTINCT keyword at the start of the SELECT list. Suppose we have a table like this:

For using DISTINCT keyword, you can use it like this: (SELECT min(ti.Country_id) . FROM tbl_countries ti . WHERE t.country_title = ti.country_title) As Country_id. , country_title. tbl_countries t. For using ROW_NUMBER(), you can use it like this: Country_id, country_title .

Dec 2, 2024 · In this article, we’ll explain various alternatives to remove duplicates in SQL, including using ROW_NUMBER (), self-joins, and GROUP BY. Each method will be explained in detail with examples and outputs. Why Remove Duplicates in SQL? Duplicate records can lead to incorrect data analysis and reporting, and can increase storage requirements.

Mar 17, 2021 · Sometimes you might need to deploy a table to the database and it is necessary to check if a table with the same name already exists to avoid duplicates. In this case, the SQL DROP TABLE IF EXISTS command can be of great help. Another way to ensure you won’t insert duplicates is using IF NOT EXISTS.

I want to avoid two INSERT INTO-SELECT statements based on some condition. Using NOT EXISTS: (id, name) t1.name. FROM TABLE_1 t1. WHERE NOT EXISTS(SELECT id. FROM TABLE_2 t2. WHERE t2.id = t1.id) Using NOT IN: (id, name) t1.name. FROM TABLE_1 t1. WHERE t1.id NOT IN (SELECT id. FROM TABLE_2) Using LEFT JOIN/IS NULL: (id, name) SELECT t1.id, t1.name.

Apr 14, 2025 · Duplicate rows in a SQL table can lead to data inconsistencies and performance issues, making it crucial to identify and remove them effectively. In this article, we will explain the process of deleting duplicate rows from a SQL table step-by-step, using SQL Server, with examples and outputs.

Duplicate rows in your SQL query results can make data harder to understand and reduce the accuracy of your analysis. When the same data appears more than once, it clutters your output and complicates reports. Solving this issue is important for maintaining clean, easy-to-read, and reliable datasets that lead to better insights and decisions ...

Feb 9, 2025 · Let me share the methods I use most often to clean up duplicate data: 1. The Quick Way: Using ROW_NUMBER () This is my favorite method because it’s clean and efficient: SELECT *, ROW_NUMBER() OVER ( PARTITION BY name, email, phone. ORDER BY id. ) as row_num. FROM customers. 2. The Safe Way: Creating a Clean Table.