SQL

select duplicates in sql

SELECT username, email, COUNT(*)
FROM users
GROUP BY username, email
HAVING COUNT(*) > 1

sql query to find duplicates in column

SELECT name, COUNT(email) 
FROM users
GROUP BY email
HAVING COUNT(email) > 1

duplicate column values sql

-- copy values from old column to new column
UPDATE tablename SET new_column = old_column

get duplicate records in sql

Multiple field=
SELECT username, email, COUNT(*)
FROM users
GROUP BY username, email
HAVING COUNT(*) > 1

Single field=
SELECT _column, COUNT(*) 
FROM _table
GROUP BY _column
HAVING COUNT(*) > 1

how to get duplicate elements in sql

• SELECT first_name, COUNT (first_name) FROM employees
GROUP BY first_name
HAVING (COUNT(first_name) > 1);

sql check duplicate value in column

SELECT columnName, COUNT(columnName)
FROM tableName
GROUP BY columnName
HAVING COUNT(columnName)>1

sql find duplicate records in two tables

SELECT  *   
FROM TableA A  
WHERE NOT EXISTS (SELECT *      
                  FROM TableB B
                  WHERE A.NUM = B.NUM);

sql query duplicate rows

/* This SQL Query will show each of those duplicate
rows individually instead of just grouping it */
SELECT username,email 
FROM `users` 
WHERE `username` 
IN (SELECT username FROM `users` GROUP BY username HAVING COUNT(username) > 1)

get duplicate entry sql

select barcode, name, count(*)
from product
group by barcode, name
HAVING count(*) > 1

sql - Count all duplicates of each value

SELECT   col,
         COUNT(dupe_col) AS dupe_cnt
FROM     TABLE
GROUP BY col
HAVING   COUNT(dupe_col) > 1
ORDER BY COUNT(dupe_col) DESC

FIND DUPLICATES IN COLUMN SQL

declare @YourTable table (id int, name varchar(10), email varchar(50))

INSERT @YourTable VALUES (1,'John','John-email')
INSERT @YourTable VALUES (2,'John','John-email')
INSERT @YourTable VALUES (3,'fred','John-email')
INSERT @YourTable VALUES (4,'fred','fred-email')
INSERT @YourTable VALUES (5,'sam','sam-email')
INSERT @YourTable VALUES (6,'sam','sam-email')

SELECT
    name,email, COUNT(*) AS CountOf
    FROM @YourTable
    GROUP BY name,email
    HAVING COUNT(*)>1

sql duplicate rows

/*SELECT hotel_id, reservation_id, COUNT(hotel_id)FROM staywhere  reservation_id is not nullGROUP BY hotel_id, reservation_idHAVING COUNT(hotel_id) > 1*/select distinct s.hotel_id , t.* from stay sright join (    select hotel_id, reservation_id, count(*) as qty    from staywhere reservation_id !=1      group by hotel_id, reservation_id    having count(*) > 1) t on s.hotel_id = t.hotel_id and s.reservation_id = t.reservation_id

duplicate a column in sql

ALTER TABLE Table1
ADD SubCategory2 {Type of subcategory 1} {NULL|NOT NULL} 
UPDATE Table1 SET SubCategory2 = SubCategory;