duplicate row mysql

1## Find ALL duplicate recods by value (without grouping them by value) ##
2# to find the duplicate, 
3# replace all instances of tableName with your table name
4# and all instances of duplicateField with the field name where you look for duplicates
5SELECT t1.*
6FROM tableName AS t1
7INNER JOIN(
8	SELECT duplicateField
9	FROM tableName
10	GROUP BY duplicateField
11	HAVING COUNT(duplicateField) > 1
12)temp ON t1.duplicateField = temp.duplicateField
13order by duplicateField

1# Duplicate rows or row
2INSERT INTO table (col1, col2, col3)
3SELECT col1, col2, col3 FROM table
4WHERE something...;

1# Duplicate row and change values in the duplicated row
2INSERT INTO table (col1, col2, col3)
3# manually insert data to the duplicated row
4SELECT "new value", "new value", "new value" FROM table
5WHERE something...;