如果我在一列中有相同的值,并且我想只返回一个而不是所有这些都是一个方法。
ArrayList<String> getAllNotes() {
Cursor cursor;
mDbHelper = mSqliteHelper.getWritableDatabase();
String query = "SELECT * FROM " + SqliteHelpers.TABLE_NAME;
cursor = mDbHelper.rawQuery(query, null);
ArrayList<String> arrayList = new ArrayList<>();
while (cursor.moveToNext()) {
String itemname = cursor.getString(cursor.getColumnIndex(SqliteHelpers.NOTES_COLUMN));
if (itemname != null) {
arrayList.add(itemname);
}
}
return arrayList;
}
正如你在图像中看到的那样,有四个项目都是相同的但我想要一个返回其他将返回正常。除了多个。image
答案 0 :(得分:0)
只需返回您想要的列:
ArrayList<String> getAllNotes() {
Cursor cursor;
mDbHelper = mSqliteHelper.getWritableDatabase();
String query = "SELECT Distinct NOTES_COLUMN FROM " + SqliteHelpers.TABLE_NAME;
cursor = mDbHelper.rawQuery(query, null);
ArrayList<String> arrayList = new ArrayList<>();
while (cursor.moveToNext()) {
String itemname = cursor.getString(cursor.getColumnIndex(SqliteHelpers.NOTES_COLUMN));
if (itemname != null) {
arrayList.add(itemname);
}
}
return arrayList;
}