Android ListView-从SQLite获取值，其中一列为分组依据

Question

I am rendering columns from SQLite table as ListView in my android application. The data looks like this:

Project Name   OutletName  param
RA_Pepsi       Tesco       Shelfstrip left
RA_Pepsi       Tesco       Shelfstrip right
RA_Cocacola    Tesco       Shelfstrip top
RA_Cocacola    Coors       Shelfstrip bottom

I am using the following code to render the ListView

sqLiteDatabase = sqLiteHelper.getWritableDatabase();
cursor = sqLiteDatabase.rawQuery("SELECT * FROM "+SQLiteHelper.TABLE_NAME2+"", null);
ProjectName_Array.clear();
OutletName_Array.clear();
ParamName_Array.clear();


if (cursor != null && cursor.getCount() > 0) {
    if (cursor.moveToFirst()) {
        do {
                    ProjectName_Array.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.Table2_Column_ProjectName)));
                    OutletName_Array.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.Table2_Column_OutletName)));
                    ParamName_Array.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.Table2_Column_PARAM)));
                } while (cursor.moveToNext());
            }
        } else {
            Toast.makeText( this, "No data to display!", Toast.LENGTH_SHORT ).show();
        }

With a custom adapter, this renders the data as ListView as follows:

RA_Pepsi
Tesco
Shelfstrip left

RA_Pepsi
Tesco
Shelfstrip right

RA_CocaCola
Tesco
Shelfstrip top

RA_CocaCola
Coors
Shelfstrip bottom

However, I want to aggregate the param at each project and store level and display as follows

RA_Pepsi
Tesco
Shelfstrip left
Shelfstrip right

RA_CocaCola
Tesco
Shelfstrip top

When I tried the group by option using both projects and outlet name columns - I get only one of the parameter rendered. How can display the list view with aggregated data.

Answer 1

Try use SQLite's group_concat() function,take a look here .

Change your sql like:

SELECT 'Project Name',OutletName,group_concat(param) as params
FROM tableName
GROUP BY 'Project Name',OutletName