[android] rawQuery(query, selectionArgs)

I want to use select query for retrieving data from table. I have found, rawQuery(query, selectionArgs) method of SQLiteDatabase class to retrieve data. But I don't know how the query and selectionArgs should be passed to rawQuery method?

This question is related to android sqlite

The answer is


String mQuery = "SELECT Name,Family From tblName";
Cursor mCur = db.rawQuery(mQuery, new String[]{});
mCur.moveToFirst();
while ( !mCur.isAfterLast()) {
        String name= mCur.getString(mCur.getColumnIndex("Name"));
        String family= mCur.getString(mCur.getColumnIndex("Family"));
        mCur.moveToNext();
}

Name and family are your result


One example of rawQuery - db.rawQuery("select * from table where column = ?",new String[]{"data"});


see below code it may help you.

String q = "SELECT * FROM customer";
Cursor mCursor = mDb.rawQuery(q, null);

or

String q = "SELECT * FROM customer WHERE _id = " + customerDbId  ;
Cursor mCursor = mDb.rawQuery(q, null);

if your SQL query is this

SELECT id,name,roll FROM student WHERE name='Amit' AND roll='7'

then rawQuery will be

String query="SELECT id, name, roll FROM student WHERE name = ? AND roll = ?";
String[] selectionArgs = {"Amit","7"} 
db.rawQuery(query, selectionArgs);

Maybe this can help you

Cursor c = db.rawQuery("query",null);
int id[] = new int[c.getCount()];
int i = 0;
if (c.getCount() > 0) 
{               
    c.moveToFirst();
    do {
        id[i] = c.getInt(c.getColumnIndex("field_name"));
        i++;
    } while (c.moveToNext());
    c.close();
}

For completeness and correct resource management:

        ICursor cursor = null;
        try
        {

            cursor = db.RawQuery("SELECT * FROM " + RECORDS_TABLE + " WHERE " + RECORD_ID + "=?", new String[] { id + "" });

            if (cursor.Count > 0)
            {
                cursor.MoveToFirst();
            }
            return GetRecordFromCursor(cursor); // Copy cursor props to custom obj
        }
        finally // IMPORTANT !!! Ensure cursor is not left hanging around ...
        {
            if(cursor != null)
                cursor.Close();
        }