database insert returning -1

I have my database as follows. I added the database and when I insert it returns -1. Is there something missing here.

rowId = db.insert(DETAILS_TABLE_CREATE, null, values);

public static final String DETAILS_TABLE_CREATE = "CREATE TABLE IF NOT EXISTS "
  + DETAILS_TABLE
  + "("
  +  DATABASE_KEY
  + " INTEGER PRIMARY KEY , "
  + DATABASE_ENT1
  + " INT, "
  + DATABASE_ ENT2
  + " INT, "
  + DATABASE_ ENT3
  + " TEXT, "
  + DATABASE_ENT4
  + " TEXT, "
  + DATABASE_ENT5
  + " REAL, "
  + DATABASE_ENT
  + " REAL, "
  + DATABASE_ENT7
  + " TEXT, "
  + DATABASE_ENT7
  + " TEXT, "
  + DATABASE_ENT8
  + " TEXT, "
  + DATABASE_ENT9
  + " TEXT, "
  + DATABASE_ENT10
  +  " TEXT, "
  + DATABASE_ENT11
  +  " TEXT, "
  + DATABASE_ENT12
  +  " TEXT "

  + ")";