How to find the repeated rows in a SQL table?

Question

which of the following is better to find the number of rows in a table?
1. count(1)
2. count(*)
3. count(rowid)

Answer 1

if you are getting repeated rows then I think there is not any primary key defined in the table so count values based on all column name.Run this script,it will return all rows which occurs more than once in the table.

  SELECT   *
    FROM
        YourTableName
    GROUP BY
        Name,PhoneNumber,Address    //if your table has three columns but it will be easy with id
    HAVING 
        COUNT(*) > 1

Answer 2

Hi, u may try like this:

select * from table_name 
 GroupBy Name.MobileNum.Address 
Having
 count(*)>1