androidsqliteandroid-cursorandroid-database

How to apply SELECT date('now') query in android?

I am working on a project and now I have been stuck on a weird stage.

I know that we can execute any query that has to do anything with database we can write that using:

Cursor cursor = db.rawQuery("SELECT * FROM table_name", null);

But now I want to execute this query:

"SELECT strftime('%s','now','-2 day')"

Generally the above query returns unixepoch time of one day before yesterday.

Does anyone know how can I get this done?

Solution

  • You would handle this query like any other query:

    Cursor cursor = db.rawQuery("SELECT strftime('%s','now','-2 day')", null);
try {
    if (cursor.moveToFirst()) {
        long seconds = cursor.getLong(0);
        ...
    } else {
        // cannot happen with this query
    }
} finally {
    cursor.close();
}

    If you want to access the column by name (which is completely pointless if you have only a single column), you can give it an alias:

    cursor = db.rawQuery("SELECT strftime(...) AS s", null);
cursor.getColumnIndexOrThrow("s");  // returns zero
...

    Please note that for queries that return a single value, there is a helper function:

    long seconds = DatabaseUtils.longForQuery(
                   db, "SELECT strftime('%s','now','-2 day')", null);