sql duplicate code example

Example 1: select duplicates in sql

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

Example 2: sql query to find duplicates in column

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

Example 3: t-sql get duplicate rows

SELECT [CaseNumber], COUNT(*) AS Occurrences
FROM [CaseCountry]
GROUP BY [CaseNumber]
HAVING (COUNT(*) > 1)

Example 4: 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

Example 5: sql how to duplicate a table

CREATE TABLE new_table LIKE original_table;
INSERT INTO new_table SELECT * FROM original_table;

Example 6: duplicate a column in sql

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