Usually we use DISTINCT or GROUP BY to fetch field by unique content. On some condition, we need to remove duplicate content in table. In MySQL there is no single command to do that. We need two queries to remove duplicate content. First, we create some table and fill it with unique result from old table. Second, we delete old table and rename the new table as the old.
Here is the code :
CREATE TABLE your_new_table as SELECT * FROM your_old_table WHERE 1 GROUP BY your_column_to_remove_duplicates;
After excute this code, check your id coloumn and set if it have primary keys and auto increment, because this script just create structure table on the fly.
Then, you just remove old and rename the new.