Question

如何在contentprovider中运行此查询？

SELECT * FROM sms_data WHERE number != (SELECT DISTINCT number from test) AND time > ?

Answer 1

首先，查询可能是错误的。而不是number != (...)您可能需要number NOT IN (...)。

假设test是您应用中的一个表而不是内容提供商，您可以分两步执行查询：

子查询SELECT DISTINCT number FROM test。从结果中构建逗号分隔的字符串，例如'12345','23456','45678'。

使用选择

进行内容提供商查询

number NOT IN (<that comma-separated list>) AND time > ?

Answer 2

对于子查询，您可以使用rawQuery（）或SQLiteQueryBuilder。

Answer 3

覆盖ContentProvider的onQuery方法，我设法将这一堆代码放在我身上。

@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
    switch (URI_MATCHER.match(uri)) {
        case TABLE1:
            Cursor cursor = database.query("sms_data", projection, selection, selectionArgs, null, null, sortOrder);
            cursor.setNotificationUri(getContext().getContentResolver(), uri);
            return cursor;
        case TABLE2:
            Cursor c = database.query(true, "test", projection, selection, selectionArgs, null, null, sortOrder, null);
            c.setNotificationUri(getContext().getContentResolver(), uri);
            return c;
        case COMBINED:
            String sql = "SELECT " + appendColumns(projection) +
                    " FROM sms_data WHERE number != IFNULL((SELECT DISTINCT number FROM test), 'abc') AND "  +  selection;
            Cursor cur = database.rawQuery(sql, selectionArgs);
            cur.setNotificationUri(getContext().getContentResolver(), uri);
            return cur;
        default:
            throw new IllegalArgumentException("Unsupported URI: " + uri + " Match = " + URI_MATCHER.match(uri));
    }
}

希望这也适合你。

Android contentprovider涉及2个表的复杂查询

3 个答案: