How do I find duplicate records in SQL?

How do I filter duplicate records in SQL?

The go to solution for removing duplicate rows from your result sets is to include the distinct keyword in your select statement. It tells the query engine to remove duplicates to produce a result set in which every row is unique. The group by clause can also be used to remove duplicates.

How do you remove duplicate records in SQL?


  1. In the output above, we have two duplicate records with ID 1 and 3. …
  2. To remove this data, replace the first Select with the SQL delete statement as per the following query. …
  3. SQL delete duplicate Rows using Common Table Expressions (CTE) …
  4. We can remove the duplicate rows using the following CTE.

How do I find duplicates and deletes in SQL?

Delete Duplicates From a Table in SQL Server

  1. Find duplicate rows using GROUP BY clause or ROW_NUMBER() function.
  2. Use DELETE statement to remove the duplicate rows.
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How do you find duplicates in queries?

Find duplicate records

  1. On the Create tab, in the Queries group, click Query Wizard.
  2. In the New Query dialog, click Find Duplicates Query Wizard > OK.
  3. In the list of tables, select the table you want to use and click Next.
  4. Select the fields that you want to match and click Next.

How do you prevent duplicate records in SOQL query?

There are three SOQL clauses that are important here.

  1. GROUP BY. Groups a set of records by the values in the field you are passing. An optional clause in SOQL queries. …
  2. HAVING. An optional clause in SOQL queries. …
  3. COUNT(FieldName) Another optional clause in SOQL queries.

How do I find duplicate records in Oracle SQL?

How to Find Duplicate Records in Oracle

  1. SELECT * FROM fruits; …
  2. SELECT fruit_name, color, COUNT(*) FROM fruits GROUP BY fruit_name, color; …
  3. SELECT fruit_name, color, COUNT(*) FROM fruits GROUP BY fruit_name, color HAVING COUNT(*) > 1;

How do you eliminate duplicate rows in SQL query without distinct?

Below are alternate solutions :

  1. Remove Duplicates Using Row_Number. WITH CTE (Col1, Col2, Col3, DuplicateCount) AS ( SELECT Col1, Col2, Col3, ROW_NUMBER() OVER(PARTITION BY Col1, Col2, Col3 ORDER BY Col1) AS DuplicateCount FROM MyTable ) SELECT * from CTE Where DuplicateCount = 1.
  2. Remove Duplicates using group By.

How do I find duplicate rows in SQL using Rowid?

Use the rowid pseudocolumn. DELETE FROM your_table WHERE rowid not in (SELECT MIN(rowid) FROM your_table GROUP BY column1, column2, column3); Where column1 , column2 , and column3 make up the identifying key for each record. You might list all your columns.

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Which command is used to suppress the duplicate records?

The uniq command is used to remove duplicate lines from a text file in Linux. By default, this command discards all but the first of adjacent repeated lines, so that no output lines are repeated. Optionally, it can instead only print duplicate lines.

Why does inner join duplicate rows?

Why does this inner join create duplicates?

Inner Join Creates Duplicate Records

  • If the Product status is Pending (In ProdMaster)
  • User is allowed to view the product (In Allowed User – User code)
  • Show the product code / Product name without duplicate.

How prevent duplicate rows in SQL JOIN?

The keyword DISTINCT is used to eliminate duplicate rows from a query result: SELECT DISTINCT … FROM A JOIN B ON … However, you can sometimes (possibly even ‘often’, but not always) avoid the need for it if the tables are organized correctly and you are joining correctly.

How do I find unique rows in SQL?


SELECT DISTINCT returns only unique (i.e. distinct) values. SELECT DISTINCT eliminates duplicate values from the results. DISTINCT can be used with aggregates: COUNT, AVG, MAX, etc. DISTINCT operates on a single column.

How do I find duplicates in row number?

Finding duplicate rows in a table can be done easily by using ROW_NUMBER() function.

This can be achieved by:

  1. Move all unique rows to TableA (all rows where [RowNumber] = 1),
  2. Move all duplicate rows to TableB (all rows where [RowNumber] <> 1),
  3. JOIN TableA with TableB to get value for [Duplicate Of].
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Why is my Access query repeating records?

Answer: Query is a way to group records; it is not a reporting tool. The query output simply shows you whether the record belongs in the query. If a field with a one-to-many relationship is in your filters, output, or sort, the record will appear multiple times– once for each time the record meets the criteria.

How do you find duplicates in Access query?

How to Find Duplicate Records in Access

  1. Launch the Query Wizard. Click Query Wizard from the Create tab in the Ribbon. …
  2. Select the Duplicates Option. …
  3. Select the Table or Query. …
  4. Select the Field/s with Potential Duplicates. …
  5. Select the extra Field/s to Display. …
  6. Name the Query. …
  7. The Results.
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