在Android上获取一个SQLite SUM在Java中 [英] Fetching a SQLite SUM in Java on Android

问题描述

我是新来的SQLite和Java，和我想要学习上飞的东西。我有一个具有一定数值在其列，我想获得它的款项，并在TextView中显示出来。

I'm new to SQLite and Java, and I'm trying to learn things on the fly. I have a column that has some numeric values in it, and I would like to get the sum of it and display it in a textview.

我目前的code是这样的：

My current code is this:

public Cursor getTotal() {
    return sqliteDatabase2.rawQuery(
        "SELECT SUM(COL_VALUES) as sum FROM myTable", null);
}

我不知道如果code是正确的，但。

I'm not sure if that code is correct, though.

我知道我应该去取那code中的结果，但我不能确定如何做到这一点。我怎样才能得到这个查询的结果到我的Java code？

I know that I'm supposed to fetch the results of that code, but I'm unsure how to do it. How can I get the results of this query into my Java code?

推荐答案

之和将返回结果与一行和一列，因此您可以使用游标读取该值：

The sum will be returned as a result with one row and one column so you can use the cursor to fetch that value:

Cursor cursor = sqliteDatabase2.rawQuery(
    "SELECT SUM(COL_VALUES) FROM myTable", null);
if(cursor.moveToFirst()) {
    return cursor.getInt(0);
}

这篇关于在Android上获取一个SQLite SUM在Java中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！