How to get a cursor with distinct values only?

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无人及你
无人及你 2020-12-21 04:45

I want to return a cursor only with distinct values of a column. The column \'Groups\' has more items but with only 2 values: 1,2,1,1,1,2,2,2,1

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  • 2020-12-21 05:03

    you can use distinct argument while making query like this:

    public Cursor query (boolean distinct, String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy, String limit)
    

    Follow this doc for more clearity.

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  • 2020-12-21 05:12

    You can have an sql query like this,

    public Cursor usingDistinct(String column_name) {
            return db.rawQuery("select DISTINCT "+column_name+" from "+TBL_NAME, null);
        }
    
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  • 2020-12-21 05:22

    You can use below example query, as you have to give column name for distinct

    Cursor cursor = db.query(true, YOUR_TABLE_NAME, new String[] { COLUMN_NAME_1 ,COLUMN_NAME_2, COLUMN_NAME_3 }, null, null, COLUMN_NAME_2, null, null, null);
    

    COLUMN_NAME_2 - name of the column for distinct.

    remember to add GROUP BY column names

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  • 2020-12-21 05:22

    Use boolean true iin the distinct argument, For example :

    public Cursor query (**true**, String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy, String limit);
    
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