Database to Cursor, Cursor to array list and array list to a string of name value pairs.

Question

I have a database table with eight columns, with the following fields:

|_id|flag|HVID|Vname|Vdate|Vtime|Vcost|Vmedicine|

I am querying on this database to extract all records which belong to a certain 'HVID':

public Cursor fetchAllVac(String ID) {

        String Key = ID;
        Cursor mCursor = mDb.query(DATABASE_TABLE1, new String[] { IDx, FLAG,
                HVID1, Vname1, VDate1, Vtime1, Vcost1, Vmedicine1 }, "HVID=?",
                new String[] { Key }, null, null, null, null);
        if (mCursor != null) {
            mCursor.moveToFirst();
        }
        return mCursor;
    }

And in the Activity, I fetch values from the cursor and store them in an Array list:

public void Vacforshare() {
    String B = null;
    ArrayList<String> mArrayList = new ArrayList<String>();
    mCursor = DBHelper.fetchAllVac(IDB);
    if (mCursor.moveToFirst()) {
        do {
            try {
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("_id")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("flag")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("HVID")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("Vname")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("Vdate")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("Vtime")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("Vcost")));
                mArrayList.add(mCursor.getString(mCursor
                        .getColumnIndex("Vmedicine")));
            } catch (Exception h) {

            }

        } while (mCursor.moveToNext());

    }
    for (int i = 0; i < mArrayList.size(); i++) {
        String G = (mArrayList.get(i));
        B = B + G;
    }
    System.out.println("" + B);

}

What I am getting in B is a redundant(all rows) string of values (My records can be of multiple rows) I want to separate these values into Name-Value pairs, I am confused as how to achieve that.

c.s. · Accepted Answer · 2013-08-01 16:41:21Z

3

You can introduce a new class that would have the list of values for one record only like below:

public class Record {
    List<String> values = new ArrayList<String>();

    public List<String> getValues() {
        return values;
    }
}

Then in your loop fill-in a list of records:

ArrayList<Record> mArrayList = new ArrayList<Record>();
do {
    try {
        Record record = new Record();
        List<String> values = record.getValues();

        values.add(mCursor.getString(mCursor.getColumnIndex("_id")));
        ...
        mArrayList.add(record);
    } catch (Exception h) {

    }
}

Now you can iterate through the field names and the values for each record to create the output you want:

String[] names = new String[] {"_id", "flag", ....};
for (int i = 0; i < mArrayList.size(); i++) {
    Record record = mArrayList.get(i);

    String current = "";
    List<String> values = record.getValues();
    for (int j = 0; j < values.size(); j++) {
        String fieldName = names[j];
        String s = values.get(j);
        current += " " + fieldName + "=" + s;
    }
    B = B + "[" + current.trim() + "]";
}
System.out.println(B); // will print: [_id=value1 flag=value2 ...][_id=value1 flag=value2 ...] etc

edited Aug 1, 2013 at 16:41

answered Aug 1, 2013 at 12:22

c.s.

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2 Comments

user2613996 Over a year ago

Gives me The method add(Record) in the type ArrayList<Record> is not applicable for the arguments (String)

c.s. Over a year ago

@user2613996 You are calling add() with a string argument. You should call it with a Record. Please check first code sample.

mihail · Accepted Answer · 2013-08-01 12:27:50Z

3

ArrayList<ArrayList<NameValuePair>> table = new ArrayList<ArrayList<NameValuePair>>();
if (mCursor.moveToFirst()) {
        do {
            ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
            try {
                nameValuePairs.add(new BasicNameValuePair("_id",mCursor.getString(mCursor.getColumnIndex("_id"))));
            //do this for the rest columns...
            //...
            //...

            table.add(nameValuePairs);

            } catch (Exception h) {

            }

        } while (mCursor.moveToNext());

in table you will have the rows as an ArrayList from NameValuePairs

after, you can get a value from a row like

ArrayList<NameValuePair> row = table.get(0);
NameValuePair column = row.get(0);
String columnName = column.getName();
String columnValue = column.getValue();

edited Aug 1, 2013 at 12:27

answered Aug 1, 2013 at 12:16

mihail

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3 Comments

user2613996 Over a year ago

This is an easier way out! Thank you!

user2613996 Over a year ago

What does the Table array list do?

mihail Over a year ago

the ArrayList<NameValuePair> repesents a row from the table. the table vairable hold the rows.

isaach1000 · Accepted Answer · 2013-08-01 12:16:57Z

1

You can make B an ArrayList of HashMaps and store the pairs in B. Put the keys in the map as you extract them from mCursor in the loop. If B must be a string, use JSON format.

answered Aug 1, 2013 at 12:16

isaach1000

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Comments

Opiatefuchs · Accepted Answer · 2013-08-01 12:18:03Z

1

but You want to have a single String for every row, like this:

String "Vname|Vdate|Vtime|Vcost|Vmedicine"
String "Vname|Vdate|Vtime|Vcost|Vmedicine"

If this is what You want, You can pass every Row to an ArrayList, and that ArrayList to an ArrayList, this looks similar to this:

      private ArrayList<ArrayList<String>> doubleArray = new ArrayList<ArrayList<String>>();

and then when You get Your values from DB:

       ArrayList<String> mArrayList = new ArrayList<String>();
       mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("_id")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("flag")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("HVID")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("Vname")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("Vdate")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("Vtime")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("Vcost")));
            mArrayList.add(mCursor.getString(mCursor
                    .getColumnIndex("Vmedicine")));

            doubleArray.add(mArrayList);

So You can get exactly one row as:

          for(int i=0;i<doubleArray.size();i++){

              String a = doubleArray.get(i)
          // now pass the String wherever You want
         }

but like I am said, I don´t know from Your explanation if this is what You want...

answered Aug 1, 2013 at 12:18

Opiatefuchs

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3 Comments

user2613996 Over a year ago

No those are my coulmn names, however I want aseparate string for each row!

Opiatefuchs Over a year ago

sure this are Your column names, I know, but like I described, You should get the values from each column/row into one array.

user2613996 Over a year ago

I will get back here! :) Thanks mate for the guidance!

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