How do I check if two rows have the same value in SQL?

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How do I check if two rows have the same value in SQL Server?

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 I select the same value in SQL?

To select duplicate values, you need to create groups of rows with the same values and then select the groups with counts greater than one. You can achieve that by using GROUP BY and a HAVING clause.

How do I find unique rows in sql?

SQL SELECT DISTINCT Explanation

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.

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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 count 1 in SQL?

1 Answer

  1. SELECT user_id ,COUNT(*) count.
  2. FROM PAYMENT.
  3. GROUP BY account,user_id ,date.
  4. Having COUNT(*) > 1.

How do I have multiple rows in one row in SQL?

STUFF Function in SQL Server

  1. Create a database.
  2. Create 2 tables as in the following.
  3. Execute this SQL Query to get the student courseIds separated by a comma. USE StudentCourseDB. SELECT StudentID, CourseIDs=STUFF. ( ( SELECT DISTINCT ‘, ‘ + CAST(CourseID AS VARCHAR(MAX)) FROM StudentCourses t2.

How can get second highest salary in SQL Server?

How To Find Second Highest Salary Using a Sub-Query

  1. SELECT TOP 1 SALARY.
  2. FROM (
  3. SELECT DISTINCT TOP 2 SALARY.
  4. FROM tbl_Employees.
  5. ORDER BY SALARY DESC.
  6. ) RESULT.
  7. ORDER BY SALARY.

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.

How do I select unique rows in mysql?

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.

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What is difference between unique and distinct?

The main difference between unique and distinct is that UNIQUE is a constraint that is used on the input of data and ensures data integrity. While DISTINCT keyword is used when we want to query our results or in other words, output the data.

How can I delete duplicate rows in SQL query?

HAVING COUNT(*) > 1;

  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 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.