How to get the number of rows of the selected result from sqlite3?

Question

I want to get the number of selected rows as well as the selected data. At the present I have to use two sql statements:

one is

select * from XXX w         


        

Answer 1

SQL can't mix single-row (counting) and multi-row results (selecting data from your tables). This is a common problem with returning huge amounts of data. Here are some tips how to handle this:

• Read the first N rows and tell the user "more than N rows available". Not very precise but often good enough. If you keep the cursor open, you can fetch more data when the user hits the bottom of the view (Google Reader does this)

• Instead of selecting the data directly, first copy it into a temporary table. The INSERT statement will return the number of rows copied. Later, you can use the data in the temporary table to display the data. You can add a "row number" to this temporary table to make paging more simple.

• Fetch the data in a background thread. This allows the user to use your application while the data grid or table fills with more data.