Common questions

How can I delete duplicate rows in SQL?

How can I delete duplicate rows in SQL?

To delete the duplicate rows from the table in SQL Server, you follow these steps:

  1. Find duplicate rows using GROUP BY clause or ROW_NUMBER() function.
  2. Use DELETE statement to remove the duplicate rows.

How do I remove duplicate rows in R?

Remove Duplicate rows in R using Dplyr – distinct () function. Distinct function in R is used to remove duplicate rows in R using Dplyr package. Dplyr package in R is provided with distinct() function which eliminate duplicates rows with single variable or with multiple variable.

How do I find duplicate rows in SQL?

How to Find Duplicate Values in SQL

  1. Using the GROUP BY clause to group all rows by the target column(s) – i.e. the column(s) you want to check for duplicate values on.
  2. Using the COUNT function in the HAVING clause to check if any of the groups have more than 1 entry; those would be the duplicate values.

How do you prevent duplicate rows in SQL?

5 Easy Ways How to Avoid Duplicate Records in SQL INSERT INTO SELECT

  1. Adding the Distinct Keyword to a Query to Eliminate Duplicates.
  2. Using SQL WHERE NOT IN to Remove Duplicate Values.
  5. Using COUNT(*) = 0 Without Duplicates.

How do I find duplicate rows in R?

Find indices of duplicated rows [duplicate] Function duplicated in R performs duplicate row search. If we want to remove the duplicates, we need just to write df[! duplicated(df),] and duplicates will be removed from data frame.

How do I remove duplicate rows from multiple columns in R?


  1. Remove duplicate rows based on one or more column values: my_data %>% dplyr::distinct(Sepal. Length)
  2. R base function to extract unique elements from vectors and data frames: unique(my_data)
  3. R base function to determine duplicate elements: duplicated(my_data)

How do I remove duplicate lines?

Check the “Case sensitive.”. Check the “Remove empty lines.”. Check the “Display removed.”. Lines are prefixed with removal information for reference. Example: Click the “Remove Duplicate Lines” button and watch these duplicate lines become one. Click the “Remove Duplicate Lines” button and watch these duplicate lines become one.

How do I remove duplicate values?

To remove duplicate values, click Data > Data Tools > Remove Duplicates. To highlight unique or duplicate values, use the Conditional Formatting command in the Style group on the Home tab.

How do you delete rows in SQL?

Follow the given steps to delete a row or column by table menu: Place insertion point in row or column which you want to delete. After clicking on Table menu, select “Delete”. You will see a submenu of Delete being displayed in front of you. To delete selected row or column from the table, select Columns or Rows or Cells command.

How do I delete duplicate records in SQL Server?

DELETE Duplicate Records Using ROWCOUNT. So to delete the duplicate record with SQL Server we can use the SET ROWCOUNT command to limit the number of rows affected by a query. By setting it to 1 we can just delete one of these rows in the table. Note: the select commands are just used to show the data prior and after the delete occurs.

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