counting rows returned in postgresql

I need to count the n开发者_JS百科umber of rows returned from database.By using following code

rv = plpy.execute("SELECT * FROM AA where name = 'active '") 
rv[0]["id"] 

works when some values are returned but I need to check if no values are returned: Can someone help please.

Why don't you just check the size of the rv array?

Why dont you use -

SELECT Count(*) as rowCount FROM AA where name = 'active'

This will return you the number of rows from the query. If there are no rows, then it will return 0.

In PL/Python, the way to get the result size is

rv.nrows

See the documentation.

.rowcount