SQL | How to print duplicate rows in a table?

To identify duplicate rows in a table, you typically use a combination of the GROUP BY and HAVING clauses in SQL. The GROUP BY clause groups the rows that have the same values in specified columns, and the HAVING clause filters the groups that have more than one row.

Here's a general approach using a hypothetical table your_table and its columns col1, col2, ..., coln:

SELECT col1, col2, ..., coln, COUNT(*)
FROM your_table
GROUP BY col1, col2, ..., coln
HAVING COUNT(*) > 1;

The query returns the distinct values of columns col1, col2, ..., coln that have duplicates, along with the count of those duplicates.

Example: Suppose you have a table called employees with columns first_name, last_name, and dob (date of birth), and you want to find duplicate rows based on these columns:

SELECT first_name, last_name, dob, COUNT(*)
FROM employees
GROUP BY first_name, last_name, dob
HAVING COUNT(*) > 1;

This query will list all the names and birth dates that appear more than once in the employees table, along with the count of their occurrences. If you only want to retrieve the duplicate values without the count, you can exclude the COUNT(*) from the SELECT clause.

Identifying Duplicate Records in SQL Table:

SELECT column1, column2, COUNT(*)
FROM your_table
GROUP BY column1, column2
HAVING COUNT(*) > 1;

Printing Duplicates in a Table Using SQL:

SELECT *
FROM your_table
WHERE column1 IN (
    SELECT column1
    FROM your_table
    GROUP BY column1
    HAVING COUNT(*) > 1
);

SQL Script to List Duplicate Rows in a Table:

SELECT column1, column2, COUNT(*)
FROM your_table
GROUP BY column1, column2
HAVING COUNT(*) > 1;

Displaying Duplicate Values in a SQL Table:

SELECT *
FROM your_table
WHERE column1 IN (
    SELECT column1
    FROM your_table
    GROUP BY column1
    HAVING COUNT(*) > 1
);

SQL SELECT Statement to Print Duplicate Rows:
- Modify the column names based on your table structure.
```
SELECT column1, column2, COUNT(*)
FROM your_table
GROUP BY column1, column2
HAVING COUNT(*) > 1;
```

Identify and Print Duplicate Data in a Table Using SQL:

SELECT *
FROM your_table
WHERE column1 IN (
    SELECT column1
    FROM your_table
    GROUP BY column1
    HAVING COUNT(*) > 1
);