如何检查记录是否已存在？

Question

如何检查数据库中是否已存在记录（ContentValues）？

public void insertData(String ActId,String Dstcode,String Mandicode,String Traderlicno,String licenseId,String licensename,String Gatepassno,String FarmerId,String Farmername,String FarmerFatherName,String CommodityGrpCode,String CommodityCode,String VartyCode,String Cwght,String UntCode,String FnlPrice,String lgndate,String Ip,String dte,String IEMIN0,String ModelNo,String BoardName,String BrandName,String SIMNo)
     {

  ContentValues cv = new ContentValues();

      cv.put(DatabaseHandler.AUCTIONINFO_ActId, ActId);
      cv.put(DatabaseHandler.AUCTIONINFO_Dstcode, Dstcode);
      cv.put(DatabaseHandler.AUCTIONINFO_Mandicode, Mandicode);
      cv.put(DatabaseHandler.AUCTIONINFO_Traderlicno, Traderlicno);
      cv.put(DatabaseHandler.AUCTIONINFO_licenseId, licenseId);
      cv.put(DatabaseHandler.AUCTIONINFO_licensename, licensename);
      cv.put(DatabaseHandler.AUCTIONINFO_Gatepassno, Gatepassno);
      cv.put(DatabaseHandler.AUCTIONINFO_FarmerId, FarmerId);
      cv.put(DatabaseHandler.AUCTIONINFO_Farmername, Farmername);
      cv.put(DatabaseHandler.AUCTIONINFO_FarmerFatherName, FarmerFatherName);
      cv.put(DatabaseHandler.AUCTIONINFO_CommodityGrpCode, CommodityGrpCode);
      cv.put(DatabaseHandler.AUCTIONINFO_CommodityCode, CommodityCode);
      cv.put(DatabaseHandler.AUCTIONINFO_VartyCode, VartyCode);
      cv.put(DatabaseHandler.AUCTIONINFO_Cwght, Cwght);
      cv.put(DatabaseHandler.AUCTIONINFO_UntCode, UntCode);
      cv.put(DatabaseHandler.AUCTIONINFO_FnlPrice, FnlPrice);
      cv.put(DatabaseHandler.AUCTIONINFO_lgndate, lgndate);
      cv.put(DatabaseHandler.AUCTIONINFO_Ip, Ip);
      cv.put(DatabaseHandler.AUCTIONINFO_dte, dte);
      cv.put(DatabaseHandler.AUCTIONINFO_IEMIN0, IEMIN0);
      cv.put(DatabaseHandler.AUCTIONINFO_ModelNo, ModelNo);
      cv.put(DatabaseHandler.AUCTIONINFO_BoardName, BoardName);
      cv.put(DatabaseHandler.AUCTIONINFO_BrandName, BrandName);
      cv.put(DatabaseHandler.AUCTIONINFO_SIMNo, SIMNo);

          database.insert(DatabaseHandler.TABLE_AUCTIONINFO, null, cv);

}

Answer 1

修改

myDB= openOrCreateDatabase("DBName", MODE_PRIVATE, null);
myDB.execSQL("CREATE TABLE IF NOT EXISTS MyTable (your query goes here);");

Cursor cursor = myDB.rawQuery("select AUCTIONINFO_ActId from TABLE_AUCTIONINFO where AUCTIONINFO_licenseId = licenseId;", null);
if(cursor.getCount()!=0)
{
  // now you can insert the record
}
else
{

}