检查行是否存在SQLite

Question

I would like to check if any row exists within the Sqlite database.

my java class

public static final String DATABASE_TABLE2 = "receivernumber";
public static final String KEY_ROWID2 = "hpnumberID2";
public static final String KEY_NAME2 = "hpNumber2";

public long insertContact2(String hpNumber2) 
{
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_NAME2, hpNumber2);
    if(CheckIsDataAlreadyInDBorNot(0) == true) {

        return db.update(
            DATABASE_TABLE2, initialValues, "SET='"+KEY_NAME2+"'" +"WHERE"+ "KEY_ROWID2="+1, null
        ) > 0;
    }
    else {
        return db.insert(DATABASE_TABLE2, null, initialValues);
    }
    //if there is alrdy a record, create a method to reject intake
    return 0;
}


public boolean CheckIsDataAlreadyInDBorNot(long hpnumberID) {

    Cursor mCursor = db.query(
        true, DATABASE_TABLE2, new String[] {KEY_ROWID, KEY_NAME},KEY_ROWID + "=" + hpnumberID, null, null, null, null, null
    );
    String Query = "Select * from " + DATABASE_TABLE2 + " where " + KEY_ROWID2 + " < " + 0;
    SQLiteDatabase sqldb = EGLifeStyleApplication.sqLiteDatabase;
    Cursor cursor = sqldb.rawQuery(Query, null);     

    if(cursor.getCount<=0) return false;

    return true;
}


public boolean updateContact2(long hpnumberID2, String hpNumber2) 
{
    ContentValues args = new ContentValues();
    args.put(KEY_NAME2, hpNumber2);

        //args.put(KEY_NAME3, Selected);
        //return db.update(DATABASE_TABLE2, args, KEY_ROWID2 + "=" + hpnumberID2, null) > 0;
        //db.execSQL("UPDATE " + DATABASE_TABLE2 + " SET " + KEY_NAME2 + " WHERE " +   KEY_ROWID2 + "=1 ");

    return db.update(DATABASE_TABLE2, args, "SET='" + KEY_NAME2 + "'" + "WHERE" + "KEY_ROWID2=" + 1, null) > 0;
}

So my database layout is such that the user can only add a number for the first time. Subsequent times the user wishes to add a number, it would be replaced by an edit function instead. However, there's an error called EGLifeStyleApplication cannot be resolved to a variable. However, as this is an answer from questions solved successfully, they did not really explain what is the function of that EGLifeStyleApplications. So how do I go about doing what I want to achieve? (How do I edit my insert statement) Thanks.

Answer 1

Replace the offending line with

sqldb = ctx.openOrCreateDatabase(DB_NAME, Context.MODE_PRIVATE, null);

where ctx is a context you will pass as a parameter to your CheckIsDataAlreadyInDBorNot method. ie:

public boolean CheckIsDataAlreadyInDBorNot(Context ctx, long hpnumberID) {

and DB_NAME is a string containing your db name, ie:

private final static String DB_NAME = "rec_nums.db";

public static final String DATABASE_TABLE2 = "receivernumber";
public static final String KEY_ROWID2 = "hpnumberID2";
public static final String KEY_NAME2 = "hpNumber2";