CODEWITHSUNDEEP
androiddatabase
user1156210
user1156210

Reputation: 151

How to delete duplicated database records?

i have a list with some items.The use can save some of them in a database,as favorites.My problem is that i m getting duplicated records in the database if he try to add the same item two times in the favorites.How can i fix it?

i was thinking something like 

ourDatabase.rawQuery("DELETE FROM "+DBHelper.DATABASE_TABLE+" WHERE"+DBHelper.NAME+" EQUALS "+DBHelper.NAME+");",null);

but it's not working.

This is my create Entry method

public void createEntry(String name, String dodes) {

         try {        
            ContentValues cv = new ContentValues();
            cv.put(NAME, name);
            cv.put(DODES, dodes);

              //  ourDatabase.rawQuery("DELETE FROM "+DBHelper.DATABASE_TABLE+" WHERE "+DBHelper.NAME+" = "+DBHelper.NAME+");",null);
                ourDatabase.insert("DB", null, cv); 

        } catch (Exception e) {
            Log.e("Exception in insert :", e.toString());
            e.printStackTrace();
        }
    }

Upvotes: 1

Views: 875

Answers (2)

Jim Rhodes
Jim Rhodes

Reputation: 5085

Before inserting, check to see if an item with the same name already exists. If so, do an update instead of an insert.

Cursor crsr = null;
try
{
  crsr = ourDatabase.rawQuery("SELECT _id FROM "+DBHelper.DATABASE_TABLE
      +" WHERE "+DBHelper.NAME+"='"+name+"'", null);
}
catch ( Exception excp )
{
  crsr = null;
}
if ( (crsr == null) || (crsr.getCount() < 1) )
  // Insert item
else
  // Update item

Upvotes: 0

Matthew Rudy
Matthew Rudy

Reputation: 16834

The simple answer is to ensure that the record is "unique".

You can do this inside the database by adding a "unique index".

We want something like

CREATE UNIQUE INDEX unique_name ON some_table(name)

So something like this in code;

"CREATE UNIQUE INDEX unique_name ON "+
DBHelper.DATABASE_TABLE+
"("+DBHelper.NAME+")"

This means that if you try and insert a duplicate, you will get an error.

Therefore you'll also need to add code that checks whether the name already exists, before you try and do it.

Upvotes: 3

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